The ligand binding domain (LBD) of retinoic acid receptor (RAR), a members of the nuclear receptor superfamily; The ligand binding domain (LBD) of retinoic acid receptor (RAR): Retinoic acid receptors are members of the nuclear receptor (NR) superfamily of ligand-regulated transcription factors. RARs mediate the biological effect of retinoids, including both naturally dietary vitamin A (retinol) metabolites and active synthetic analogs. Retinoids play key roles in a wide variety of essential biological processes, such as vertebrate embryonic morphogenesis and organogenesis, differentiation and apoptosis, and homeostasis. RARs function as heterodimers with retinoic X receptors by binding to specific RAR response elements (RAREs) found in the promoter regions of retinoid target genes. In the absence of ligand, the RAR-RXR heterodimer recruits the corepressor proteins NCoR or AMRT, and associated factors such as histone deacetylases or DNA-methyltransferases, leading to an inactive condensed chromatin structure, preventing transcription. Upon ligand binding, the corepressors are released, and coactivator complexes such as histone acetyltransferase or histone arginine methyltransferases are recruited to activate transcription. There are three RAR subtypes (alpha, beta, gamma), originating from three distinct genes. For each subtype, several isoforms exist that differ in their N-terminal region, allowing retinoids to exert their pleiotropic effects. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, retinoic acid receptors have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a non-conserved hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 188 ELITKVSKAHQETFPSLCQLGKYTTNSSADHRVQLDLGLWDKFSELATKCIIKIVEFAKRLPGFTGLSIADQITLLKAAC 267
Cdd:cd06937    1 DLITKVRKAHQETFPSLCQLGKYTTNSSADQRVRLDLGLWDKFSELSTKCIIKIVEFAKRLPGFTTLTIADQITLLKAAC 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 268 LDILMLRICTRYTPEQDTMTFSDGLTLNRTQMHNAGFGPLTDLVFAFAGQLLPLEMDDTETGLLSAICLICGDRMDLEEP 347
Cdd:cd06937   81 LDILILRICTRYTPEQDTMTFSDGLTLNRTQMHNAGFGPLTDLVFTFANQLLPLEMDDTEIGLLSAICLICGDRQDLEEP 160

                        170       180       190       200       210       220       230
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 207028980 348 EKVDKLQEPLLEALRLYARRRRPSQPYMFPRMLMKITDLRGISTKGAERAITLKMEIPGPMPPLIREMLEN 418
Cdd:cd06937  161 DRVEKLQEPLLEALKIYARKRRPDKPHMFPKMLMKITDLRSISAKGAERVITLKMEIPGPMPPLISEMLEN 231

The ligand binding domain (LBD) of retinoic acid receptor (RAR), a members of the nuclear receptor superfamily; The ligand binding domain (LBD) of retinoic acid receptor (RAR): Retinoic acid receptors are members of the nuclear receptor (NR) superfamily of ligand-regulated transcription factors. RARs mediate the biological effect of retinoids, including both naturally dietary vitamin A (retinol) metabolites and active synthetic analogs. Retinoids play key roles in a wide variety of essential biological processes, such as vertebrate embryonic morphogenesis and organogenesis, differentiation and apoptosis, and homeostasis. RARs function as heterodimers with retinoic X receptors by binding to specific RAR response elements (RAREs) found in the promoter regions of retinoid target genes. In the absence of ligand, the RAR-RXR heterodimer recruits the corepressor proteins NCoR or AMRT, and associated factors such as histone deacetylases or DNA-methyltransferases, leading to an inactive condensed chromatin structure, preventing transcription. Upon ligand binding, the corepressors are released, and coactivator complexes such as histone acetyltransferase or histone arginine methyltransferases are recruited to activate transcription. There are three RAR subtypes (alpha, beta, gamma), originating from three distinct genes. For each subtype, several isoforms exist that differ in their N-terminal region, allowing retinoids to exert their pleiotropic effects. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, retinoic acid receptors have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a non-conserved hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 188 ELITKVSKAHQETFPSLCQLGKYTTNSSADHRVQLDLGLWDKFSELATKCIIKIVEFAKRLPGFTGLSIADQITLLKAAC 267
Cdd:cd06937    1 DLITKVRKAHQETFPSLCQLGKYTTNSSADQRVRLDLGLWDKFSELSTKCIIKIVEFAKRLPGFTTLTIADQITLLKAAC 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 268 LDILMLRICTRYTPEQDTMTFSDGLTLNRTQMHNAGFGPLTDLVFAFAGQLLPLEMDDTETGLLSAICLICGDRMDLEEP 347
Cdd:cd06937   81 LDILILRICTRYTPEQDTMTFSDGLTLNRTQMHNAGFGPLTDLVFTFANQLLPLEMDDTEIGLLSAICLICGDRQDLEEP 160

                        170       180       190       200       210       220       230
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 207028980 348 EKVDKLQEPLLEALRLYARRRRPSQPYMFPRMLMKITDLRGISTKGAERAITLKMEIPGPMPPLIREMLEN 418
Cdd:cd06937  161 DRVEKLQEPLLEALKIYARKRRPDKPHMFPKMLMKITDLRSISAKGAERVITLKMEIPGPMPPLISEMLEN 231

Zinc finger, C4 type (two domains); In nearly all cases, this is the DNA binding domain of a nuclear hormone receptor. The alignment contains two Zinc finger domains that are too dissimilar to be aligned with each other.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 207028980   89 PCFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMS 156
Cdd:pfam00105   1 LCKVCGDKASGYHYGVLTCEGCKGFFRRSIQKNIVYTCKFNKDCVIDKRNRNRCQYCRLKKCLEVGMS 68

Ligand binding domain of hormone receptors;

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980   234 ATKCIIKIVEFAKRLPGFTGLSIADQITLLKAACLDILMLRICTRYTPEQDTMTFSDGLTLNRTQMHNA----GFGPLTD 309
Cdd:smart00430   1 AERQLLLTVEWAKSFPGFRELSLEDQIVLLKSFWFELLLLELAYRSVKLKKELLLAPDGTYIRPDAVLElrklFSPFLDR 80

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980   310 LVFAFAGQLLPLEMDDTETGLLSAICLICGDRMDLEEP--EKVDKLQEPLLEALRLYARRRRPSQPYM-FPRMLMKITDL 386
Cdd:smart00430  81 ILSELVKPLRELKLDDEEYALLKAIVLFNPAVPGLSEEgkEIVEKLQEKYANALHDYYLKNYPMNYPGrFAKLLLILPEL 160

                   .
gi 207028980   387 R 387
Cdd:smart00430 161 R 161

The ligand binding domain (LBD) of retinoic acid receptor (RAR), a members of the nuclear receptor superfamily; The ligand binding domain (LBD) of retinoic acid receptor (RAR): Retinoic acid receptors are members of the nuclear receptor (NR) superfamily of ligand-regulated transcription factors. RARs mediate the biological effect of retinoids, including both naturally dietary vitamin A (retinol) metabolites and active synthetic analogs. Retinoids play key roles in a wide variety of essential biological processes, such as vertebrate embryonic morphogenesis and organogenesis, differentiation and apoptosis, and homeostasis. RARs function as heterodimers with retinoic X receptors by binding to specific RAR response elements (RAREs) found in the promoter regions of retinoid target genes. In the absence of ligand, the RAR-RXR heterodimer recruits the corepressor proteins NCoR or AMRT, and associated factors such as histone deacetylases or DNA-methyltransferases, leading to an inactive condensed chromatin structure, preventing transcription. Upon ligand binding, the corepressors are released, and coactivator complexes such as histone acetyltransferase or histone arginine methyltransferases are recruited to activate transcription. There are three RAR subtypes (alpha, beta, gamma), originating from three distinct genes. For each subtype, several isoforms exist that differ in their N-terminal region, allowing retinoids to exert their pleiotropic effects. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, retinoic acid receptors have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a non-conserved hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 188 ELITKVSKAHQETFPSLCQLGKYTTNSSADHRVQLDLGLWDKFSELATKCIIKIVEFAKRLPGFTGLSIADQITLLKAAC 267
Cdd:cd06937    1 DLITKVRKAHQETFPSLCQLGKYTTNSSADQRVRLDLGLWDKFSELSTKCIIKIVEFAKRLPGFTTLTIADQITLLKAAC 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 268 LDILMLRICTRYTPEQDTMTFSDGLTLNRTQMHNAGFGPLTDLVFAFAGQLLPLEMDDTETGLLSAICLICGDRMDLEEP 347
Cdd:cd06937   81 LDILILRICTRYTPEQDTMTFSDGLTLNRTQMHNAGFGPLTDLVFTFANQLLPLEMDDTEIGLLSAICLICGDRQDLEEP 160

                        170       180       190       200       210       220       230
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 207028980 348 EKVDKLQEPLLEALRLYARRRRPSQPYMFPRMLMKITDLRGISTKGAERAITLKMEIPGPMPPLIREMLEN 418
Cdd:cd06937  161 DRVEKLQEPLLEALKIYARKRRPDKPHMFPKMLMKITDLRSISAKGAERVITLKMEIPGPMPPLISEMLEN 231

DNA-binding domain of retinoic acid receptor (RAR) is composed of two C4-type zinc fingers; DNA-binding domain of retinoic acid receptor (RAR) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. RAR interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. RARs mediate the biological effect of retinoids, including both natural dietary vitamin A (retinol) metabolites and active synthetic analogs. Retinoids play key roles in a wide variety of essential biological processes, such as vertebrate embryonic morphogenesis and organogenesis, differentiation and apoptosis, and homeostasis. RAR function as a heterodimer with retinoic X receptor by binding to specific RAR response elements (RAREs), which are composed of two direct repeats of the consensus sequence 5'-AGGTCA-3' separated by one to five base pair and found in the promoter regions of retinoid target genes. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, retinoic acid receptors have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a non-conserved hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980  85 RVYKPCFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAVRNDR 164
Cdd:cd06964    2 RIYKPCFVCQDKSSGYHYGVSACEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKESVRNDR 81

                 .
gi 207028980 165 N 165
Cdd:cd06964   82 N 82

DNA-binding domain of nuclear receptors is composed of two C4-type zinc fingers; DNA-binding domain of nuclear receptors is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. It interacts with a specific DNA site upstream of the target gene and modulates the rate of transcriptional initiation. Nuclear receptors form a superfamily of ligand-activated transcription regulators, which regulate various physiological functions, from development, reproduction, to homeostasis and metabolism in animals (metazoans). The family contains not only receptors for known ligands but also orphan receptors for which ligands do not exist or have not been identified. NRs share a common structural organization with a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD). Most nuclear receptors bind as homodimers or heterodimers to their target sites, which consist of two hexameric half-sites. Specificity is determined by the half-site sequence, the relative orientation of the half-sites and the number of spacer nucleotides between the half-sites. However, a growing number of nuclear receptors have been reported to bind to DNA as monomers.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 207028980  90 CFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAVR 161
Cdd:cd06916    1 CAVCGDKASGYHYGVLTCEGCKGFFRRSVRRNLEYTCPAGGNCVIDKRNRNRCQACRLKKCLAVGMRKEAVR 72

The ligand binding domain of Liver X receptors, a family of nuclear receptors of ligand-activated transcription factors; The ligand binding domain of Liver X receptors: Liver X receptors (LXRs) belong to a family of nuclear receptors of ligand-activated transcription factors. LXRs operate as cholesterol sensors which protect from cholesterol overload by stimulating reverse cholesterol transport from peripheral tissues to the liver and its excretion in the bile. Oxidized cholesterol derivatives or oxysterols were identified as specific ligands for LXRs. Upon ligand binding a conformational change leads to recruitment of co-factors, which stimulates expression of target genes. Among the LXR target genes are several genes involved in cholesterol efflux from peripheral tissues such as the ATP-binding-cassette transporters ABCA1, ABCG1 and ApoE. There are two LXR isoforms in mammals, LXRalpha and LXRbeta. LXRalpha is expressed mainly in the liver, intestine, kidney, spleen, and adipose tissue, whereas LXRbeta is ubiquitously expressed at lower level. Both LXRalpha and LXRbeta function as heterodimers with the retinoid X receptor (RX R) which may be activated by either LXR ligands or 9-cis retinoic acid, a specific RXR ligand. The LXR/RXR complex binds to a liver X receptor response element (LXRE) in the promoter region of target genes. LXR has typical NR modular structure with a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and the ligand binding domain (LBD) at the C-terminal.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 230 FSELATKCIIKIVEFAKRLPGFTGLSIADQITLLKAACLDILMLRICTRYTPEQDTMTFSDGLTLNRTQMHNAGF-GPLT 308
Cdd:cd06954   48 FTELAILSVQEIVDFAKQLPGFLTLTREDQIALLKASTIEVMLLETARRYNPESEAITFLKDFPYSRDDFARAGLqVEFI 127

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 309 DLVFAFAGQLLPLEMDDTETGLLSAICLICGDRMDLEEPEKVDKLQEPLLEALRLYARRRRPSQPYMFPRMLMKITDLRG 388
Cdd:cd06954  128 NPIFEFSKSMRELQLDDAEYALLIAINIFSADRPNVQDHHRVERLQETYVEALHSYIKIKRPSDRLMFPRMLMKLVSLRT 207

                        170       180
                 ....*....|....*....|....*..
gi 207028980 389 ISTKGAERAITLKMEiPGPMPPLIREM 415
Cdd:cd06954  208 LSSVHSEQVFALRLQ-DKKLPPLLSEI 233

DNA-binding domain of heptocyte nuclear factor 4 (HNF4) is composed of two C4-type zinc fingers; DNA-binding domain of hepatocyte nuclear factor 4 (HNF4) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. HNF4 interacts with a DNA site, composed of two direct repeats of AGTTCA with 1 bp spacer, which is upstream of target genes and modulates the rate of transcriptional initiation. HNF4 is a member of the nuclear receptor superfamily. HNF4 plays a key role in establishing and maintenance of hepatocyte differentiation in the liver. It is also expressed in gut, kidney, and pancreatic beta cells. HNF4 was originally classified as an orphan receptor, but later it is found that HNF4 binds with very high affinity to a variety of fatty acids. However, unlike other nuclear receptors, the ligands do not act as a molecular switch for HNF4. They seem to constantly bind to the receptor, which is constitutively active as a transcription activator. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, HNF4 has a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 207028980  90 CFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAVRNDR 164
Cdd:cd06960    1 CAVCGDRATGKHYGVLSCNGCKGFFRRSVRKNRTYTCRFGGNCVVDKDKRNACRYCRFKKCLEVGMDPEAVQNER 75

DNA-binding domain of Retinoid-related orphan receptors (RORs) is composed of two C4-type zinc fingers; DNA-binding domain of Retinoid-related orphan receptors (RORs) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which coordinates a single zinc atom. ROR interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. RORS are key regulators of many physiological processes during embryonic development. RORs bind as monomers to specific ROR response elements (ROREs) consisting of the consensus core motif AGGTCA preceded by a 5-bp A/T-rich sequence. There are three subtypes of retinoid-related orphan receptors (RORs), alpha, beta, and gamma, which differ only in N-terminal sequence and are distributed in distinct tissues. RORalpha plays a key role in the development of the cerebellum particularly in the regulation of the maturation and survival of Purkinje cells. RORbeta expression is largely restricted to several regions of the brain, the retina, and pineal gland. RORgamma is essential for lymph node organogenesis. Recently, it has been suggested that cholesterol or a cholesterol derivative are the natural ligands of RORalpha. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, retinoid-related orphan receptors have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a non-conserved hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 207028980  89 PCFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAVRNDR 164
Cdd:cd06968    7 PCKICGDKSSGIHYGVITCEGCKGFFRRSQQNNVSYSCPRQKNCLIDRTNRNRCQHCRLQKCLALGMSRDAVKFGR 82

DNA-binding domain of the TR2 and TR4 (human testicular receptor 2 and 4) is composed of two C4-type zinc fingers; DNA-binding domain of the TR2 and TR4 (human testicular receptor 2 and 4) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which coordinates a single zinc atom. TR2 and TR4 interact with specific DNA sites upstream of the target gene and modulate the rate of transcriptional initiation. TR4 and TR2 are orphan nuclear receptors; the physiological ligand is as yet unidentified. TR2 is abundantly expressed in the androgen-sensitive prostate. TR4 transcripts are expressed in many tissues, including central nervous system, adrenal gland, spleen, thyroid gland, and prostate. It has been shown that human TR2 binds to a wide spectrum of natural hormone response elements (HREs) with distinct affinities suggesting that TR2 may cross-talk with other gene expression regulation systems. The genes responding to TR2 or TR4 include genes that are regulated by retinoic acid receptor, vitamin D receptor, and peroxisome proliferator-activated receptor. TR4/2 binds to HREs as dimers. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, TR2-like receptors have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980  85 RVYKPCFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAVRNDR 164
Cdd:cd06967    1 QPVELCVVCGDKASGRHYGAVSCEGCKGFFKRSIRKNLGYSCRGSKDCVINKHHRNRCQYCRLQKCLAMGMKSDSVQCER 80

DNA-binding domain of the orphan nuclear receptor, nerve growth factor-induced-B; DNA-binding domain (DBD) of the orphan nuclear receptor, nerve growth factor-induced-B (NGFI-B) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. NGFI-B interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. NGFI-B is a member of the nuclear-steroid receptor superfamily. NGFI-B is classified as an orphan receptor because no ligand has yet been identified. NGFI-B is an early immediate gene product of embryo development that is rapidly produced in response to a variety of cellular signals including nerve growth factor. It is involved in T-cell-mediated apoptosis, as well as neuronal differentiation and function. NGFI-B regulates transcription by binding to a specific DNA target upstream of its target genes and regulating the rate of transcriptional initiation. NGFI-B binds to the NGFI-B response element (NBRE) 5'-(A/T)AAAGGTCA as a monomer. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, NGFI-B has a central well-conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 207028980  88 KPCFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAVR 161
Cdd:cd06969    1 GLCAVCGDNAACQHYGVRTCEGCKGFFKRTVQKNAKYVCLANKNCPVDKRRRNRCQYCRFQKCLQVGMVKEVVR 74

The ligand binding domain of Drosophila ecdysone-induced protein 78, a member of the nuclear receptor superfamily; The ligand binding domain (LBD) of Drosophila ecdysone-induced protein 78 (E78) like: Drosophila ecdysone-induced protein 78 (E78) is a transcription factor belonging to the nuclear receptor superfamily. E78 is a product of the ecdysone-inducible gene found in an early late puff locus at position 78C during the onset of Drosophila metamorphosis. Two isoforms of E78, E78A and E78B, are expressed from two nested transcription units. An E78 orthologue from the Platyhelminth Schistosoma mansoni (SmE78) has also been identified. It is the first E78 orthologue known outside of the molting animals--the Ecdysozoa. SmE78 may be involved in transduction of an ecdysone signal in S. mansoni, consistent with its function in Drosophila. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, E78-like receptors have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a non-conserved hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 226 LWDKFSELATKCIIKIVEFAKRLPGFTGLSIADQITLLKAACLDILMLRICTRYTPEQDTMTFSDGLTLNRTQMhNAGFG 305
Cdd:cd06941    3 LWQQLSEALTPSVQRVVEFAKRIPGFCDLSQDDQLLLIKAGFFEVWLVRISRLINSKSGSITFDDGISISRQQL-DIIYD 81

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 306 P-LTDLVFAFAGQLLPLEMDDTETGLLSAICLICGDRMDLEEPEKVDKLQEPLLEALRLYARRRRPSQPYMFPRMLMKIT 384
Cdd:cd06941   82 SdFVKALFEFSDSFNSLGLSDTEVALFCAVVLLSPDRIGLSEPKKVAILQDRVLEALKVQVSRNRPAEAQLFASLLMKIP 161

                        170       180       190
                 ....*....|....*....|....*....|....
gi 207028980 385 DLRGISTKGAERAITLKMEIPGP-MPPLIREMLE 417
Cdd:cd06941  162 ELRSIGAKHQMHLDWYRVNWPLLrLPPLFAEIYD 195

The ligand binding domain of REV-ERB receptors, members of the nuclear receptor superfamily; The ligand binding domain (LBD) of REV-ERB receptors: REV-ERBs are transcriptional regulators belonging to the nuclear receptor superfamily. They regulate a number of physiological functions including the circadian rhythm, lipid metabolism, and cellular differentiation. The LBD domain of REV-ERB is unusual in the nuclear receptor family by lacking the AF-2 region that is responsible for coactivator interaction. REV-ERBs act as constitutive repressors because of their inability to bind coactivators. REV-ERB receptors can bind to two classes of DNA response elements as either a monomer or heterodimer, indicating functional diversity. When bound to the DNA, they recruit corepressors (NcoR/histone deacetylase 3) to the promoter, resulting in repression of the target gene. The porphyrin heme has been demonstrated to function as a ligand for REV-ERB. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, REV-ERB receptors have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a non-conserved hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 226 LWDKFSELATKCIIKIVEFAKRLPGFTGLSIADQITLLKAACLDILMLRICTRYTPEQDTMTFSDGLTLNRTQMHNAGFG 305
Cdd:cd06940   13 IWEEFSMSFTPAVREVVEFAKRIPGFRDLSQHDQVTLLKAGTFEVLMVRFASLFDAKERSVTFLSGQKYSVDDLHSMGAG 92

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 306 PLTDLVFAFAGQLLPLEMDDTETGLLSAICLICGDRMDLEEPEKVDKLQEPLLEALRLYARRRRPSQPYMFPRMLMKITD 385
Cdd:cd06940   93 DLLNSMFDFSEKLNSLQLSDEEMGLFTAVVLVSADRSGLENVNLVEALQETLIRALRTLIAKNHPNEPSIFTKLLLKLPD 172

                        170
                 ....*....|....*..
gi 207028980 386 LRGISTKGAERAITLKM 402
Cdd:cd06940  173 LRTLNNLHSEKLLAFKV 189

DNA-binding domain of ecdysone-induced DHR4 orphan nuclear receptor is composed of two C4-type zinc fingers; DNA-binding domain of ecdysone-induced DHR4 orphan nuclear receptor is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which coordinates a single zinc atom. This domain interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. Ecdysone-induced orphan receptor DHR4 is a member of the nuclear receptor family. DHR4 is expressed during the early Drosophila larval development and is induced by ecdysone. DHR4 coordinates growth and maturation in Drosophila by mediating endocrine response to the attainment of proper body size during larval development. Mutations in DHR4 result in shorter larval development which translates into smaller and lighter flies. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, DHR4 has a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980  85 RVYKPCFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAVRNDR 164
Cdd:cd07168    4 ESPKLCSICEDKATGLHYGIITCEGCKGFFKRTVQNKRVYTCVGDGRCEITKAQRNRCQYCRFRKCIRKGMMLAAVREDR 83

DNA-binding domain of retinoid X receptor (RXR) is composed of two C4-type zinc fingers; DNA-binding domain of retinoid X receptor (RXR) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. RXR functions as a DNA binding partner by forming heterodimers with other nuclear receptors including CAR, FXR, LXR, PPAR, PXR, RAR, TR, and VDR. All RXR heterodimers preferentially bind response elements composed of direct repeats of two AGGTCA sites with a 1-5 bp spacer. RXRs can play different roles in these heterodimers. RXR acts either as a structural component of the heterodimer complex, required for DNA binding but not acting as a receptor, or as both a structural and a functional component of the heterodimer, allowing 9-cis RA to signal through the corresponding heterodimer. In addition, RXR can also form homodimers, functioning as a receptor for 9-cis RA, independently of other nuclear receptors. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, RXR has a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 207028980  90 CFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAVRNDR 164
Cdd:cd06956    3 CAICGDRASGKHYGVYSCEGCKGFFKRTVRKDLTYTCRDNKDCLIDKRQRNRCQYCRYQKCLAMGMKREAVQEER 77

The DNA-binding domain of peroxisome proliferator-activated receptors (PPAR) like nuclear receptor family; The DNA-binding domain of peroxisome proliferator-activated receptors (PPAR) like nuclear receptor family is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. These domains interact with specific DNA sites upstream of the target gene and modulate the rate of transcriptional initiation. This family includes three known types of nuclear receptors: peroxisome proliferator-activated receptors (PPAR), REV-ERB receptors and Drosophila ecdysone-induced protein 78 (E78). Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, PPAR-like receptors have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a non-conserved hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 207028980  90 CFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYT-CHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAVR 161
Cdd:cd07158    1 CKVCGDKASGFHYGVHSCEGCKGFFRRTIQHNLTYRrCLNGGKCVIQRKNRNRCQYCRFKKCLSVGMSRNAVR 73

DNA-binding domain of peroxisome proliferator-activated receptors (PPAR) is composed of two C4-type zinc fingers; DNA-binding domain of peroxisome proliferator-activated receptors (PPAR) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. PPAR interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily of ligand-activated transcription factors. PPARs play important roles in regulating cellular differentiation, development and lipid metabolism. Activated PPAR forms a heterodimer with the retinoid X receptor (RXR) that binds to the hormone response elements, which are composed of two direct repeats of the consensus sequence 5'-AGGTCA-3' separated by one to five base pair located upstream of the peroxisome proliferator responsive genes, and interacts with co-activators. Several essential fatty acids, oxidized lipids and prostaglandin J derivatives can bind and activate PPAR. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, PPAR has a central well conserved DNA binding domain (DBD), a variable N-terminal regulatory domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 207028980  89 PCFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVY-TChrDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAVRNDR 164
Cdd:cd06965    1 ECRVCGDKASGFHYGVHACEGCKGFFRRTIRLKLVYkPC--DLSCKIHKKSRNKCQYCRFQKCLNVGMSHNAIRFGR 75

DNA-binding domain of estrogen receptor (ER) and estrogen related receptors (ERR) is composed of two C4-type zinc fingers; DNA-binding domains of estrogen receptor (ER) and estrogen related receptors (ERR) are composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. ER and ERR interact with the palindromic inverted repeat, 5'GGTCAnnnTGACC-3', upstream of the target gene and modulate the rate of transcriptional initiation. ERR and ER are closely related and share sequence similarity, target genes, co-regulators and promoters. While ER is activated by endogenous estrogen, ERR lacks the ability to bind to estrogen. Estrogen receptor mediates the biological effects of hormone estrogen by the binding of the receptor dimer to estrogen response element of target genes. However, ERRs seem to interfere with the classic ER-mediated estrogen responsive signaling by targeting the same set of genes. ERRs and ERs exhibit the common modular structure with other nuclear receptors. They have a central highly conserved DNA binding domain (DBD), a non-conserved N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 207028980  90 CFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAVRNDR 164
Cdd:cd07155    1 CLVCGDIASGYHYGVASCEACKAFFKRTIQGNLGYSCPSTSECEVDKKRRKSCQACRLQKCLKVGMLKEGVRLDR 75

DNA-binding domain of Tailless (TLX) is composed of two C4-type zinc fingers; DNA-binding domain of Tailless (TLX) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. TLX interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. TLX is an orphan receptor that is expressed by neural stem/progenitor cells in the adult brain of the subventricular zone (SVZ) and the dentate gyrus (DG). It plays a key role in neural development by promoting cell cycle progression and preventing apoptosis in the developing brain. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, TLX has a central well conserved DNA-binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 207028980  89 PCFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDK--NCIINKVTRNRCQYCRLQKCFEVGMSKEAVRNDR 164
Cdd:cd07163    8 PCKVCGDRSSGKHYGIYACDGCSGFFKRSIRRNRQYVCKSKGqgGCPVDKTHRNQCRACRLKKCFEVGMNKDAVQHER 85

DNA-binding domain of estrogen receptors (ER) is composed of two C4-type zinc fingers; DNA-binding domain of estrogen receptors (ER) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which coordinates a single zinc atom. ER interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. Estrogen receptor is a transcription regulator that mediates the biological effects of hormone estrogen. The binding of estrogen to the receptor triggers the dimerization and the binding of the receptor dimer to estrogen response element, which is a palindromic inverted repeat: 5'GGTCAnnnTGACC-3', of target genes. Through ER, estrogen regulates development, reproduction and homeostasis. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, ER has a central well-conserved DNA binding domain (DBD), a variable N-terminal domain, a non-conserved hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 207028980  90 CFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAVRNDR 164
Cdd:cd07171    6 CAVCSDYASGYHYGVWSCEGCKAFFKRSIQGHNDYICPATNQCTIDKNRRKSCQACRLRKCYEVGMMKGGIRRER 80

The DNA-binding domain of vitamin D receptors (VDR) like nuclear receptor family is composed of two C4-type zinc fingers; The DNA-binding domain of vitamin D receptors (VDR) like nuclear receptor family is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. This domain interacts with specific DNA site upstream of the target gene and modulates the rate of transcriptional initiation. This family includes three types of nuclear receptors: vitamin D receptors (VDR), constitutive androstane receptor (CAR) and pregnane X receptor (PXR). VDR regulates calcium metabolism, cellular proliferation and differentiation. PXR and CAR function as sensors of toxic byproducts of cell metabolism and of exogenous chemicals, to facilitate their elimination. The DNA binding activity is regulated by their corresponding ligands. VDR is activated by Vitamin D; CAR and PXR respond to a diverse array of chemically distinct ligands, including many endogenous compounds and clinical drugs. Like other nuclear receptors, xenobiotic receptors have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 207028980  90 CFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKEAV 160
Cdd:cd07156    1 CGVCGDRATGYHFNAMTCEGCKGFFRRSMKRKARFTCPFNGDCEITKDNRRHCQACRLKKCLDIGMKKEMI 71

DNA-binding domain of the photoreceptor cell-specific nuclear receptor (PNR) like is composed of two C4-type zinc fingers; The DNA-binding domain of the photoreceptor cell-specific nuclear receptor (PNR) nuclear receptor-like family is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which coordinates a single zinc atom. PNR interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. This family includes nuclear receptor Tailless (TLX), photoreceptor cell-specific nuclear receptor (PNR) and related receptors. TLX is an orphan receptor that plays a key role in neural development by regulating cell cycle progression and exit of neural stem cells in the developing brain. PNR is expressed only in the outer layer of retinal photoreceptor cells. It may be involved in the signaling pathway regulating photoreceptor differentiation and/or maintenance. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, PNR-like receptors have a central well-conserved DNA-binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 207028980  90 CFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDK-NCIINKVTRNRCQYCRLQKCFEVGMSKEAVRNDR 164
Cdd:cd06957    1 CKVCGDKSYGKHYGVYCCDGCSCFFKRSVRKGIIYTCIAGNgNCVVDKARRNWCPFCRLQKCFAVGMNRAAVQEER 76

The ligand binding domain of Nurr1, a member of conserved family of nuclear receptors; The ligand binding domain of Nerve growth factor-induced-B (NGFI-B): NGFI-B is a member of the nuclear#steroid receptor superfamily. NGFI-B is classified as an orphan receptor because no ligand has yet been identified. NGFI-B is an early immediate gene product of the embryo development that is rapidly produced in response to a variety of cellular signals including nerve growth factor. It is involved in T-cell-mediated apoptosis, as well as neuronal differentiation and function. NGFI-B regulates transcription by binding to a specific DNA target upstream of its target genes and regulating the rate of transcriptional initiation. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, NGFI-B has a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 189 LITKVSKAHQETFPSLCQLGKYT-TNSSADHRVQLDLGLWDKFSELATKCIIKIVEFAKRLPGFTGLSIADQITLLKAAC 267
Cdd:cd07348    4 LIASLVRAHIDSNPSSAKLDYSKfQESVSPLFEKEDASDIQQFYDLLSGSLEVIRKWAEKIPGFSDFCKEDQELLLESAF 83

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 268 LDILMLRICTRYTPEQDTMTFSDGLTLNRTQMHNaGFGPLTDLVFAFAGQLLPLEMDDTETGLLSAICLICgDRMDLEEP 347
Cdd:cd07348   84 VELFILRLAYRSNPEEGKLIFCNGVVLHRTQCVR-GFGDWIDSILEFSQSLHRMNLDVSAFSCLAALVIIT-DRHGLKEP 161

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 207028980 348 EKVDKLQEPLLE--ALRLYARRRRPSQPYMFPRMLMKITDLRGISTKGAERAITLKMEIPGPMPPLI 412
Cdd:cd07348  162 KRVEELQNRLISclKEHVSGSASEPQRPNCLSRLLGKLPELRTLCTQGLQRIFYLKLEDLVPPPPIV 228

DNA-binding domain of the photoreceptor cell-specific nuclear receptor (PNR) is composed of two C4-type zinc fingers; DNA-binding domain of the photoreceptor cell-specific nuclear receptor (PNR) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. PNR interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. PNR is a member of the nuclear receptor superfamily of the ligand-activated transcription factors. PNR is expressed only in the outer layer of retinal photoreceptor cells. It may be involved in the signaling pathway regulating photoreceptor differentiation and/or maintenance. It most likely binds to DNA as a homodimer. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, PNR has a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 207028980  90 CFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDK-NCIINKVTRNRCQYCRLQKCFEVGMSKEAVRNDR 164
Cdd:cd06970    9 CRVCGDTSSGKHYGIYACNGCSGFFKRSVRRKLIYRCQAGTgMCPVDKAHRNQCQACRLKKCLQAGMNKDAVQNER 84

The ligand binding domain of peroxisome proliferator-activated receptors; The ligand binding domain (LBD) of peroxisome proliferator-activated receptors (PPAR): Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily of ligand-activated transcription factors. PPARs play important roles in regulating cellular differentiation, development and lipid metabolism. Activated PPAR forms a heterodimer with the retinoid X receptor (RXR) that binds to the hormone response element located upstream of the peroxisome proliferator responsive genes and interacts with co-activators. There are three subtypes of peroxisome proliferator activated receptors, alpha, beta (or delta), and gamma, each with a distinct tissue distribution. Several essential fatty acids, oxidized lipids and prostaglandin J derivatives can bind and activate PPAR. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, PPAR has a central well conserved DNA binding domain (DBD), a variable N-terminal regulatory domain, a flexible hinge a nd a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 238 IIKIVEFAKRLPGFTGLSIADQITLLKAACLDILMLRICTRYTpeQDTMTFSDG---LTLNRTQMHNAGFGPLTDLVFAF 314
Cdd:cd06932   76 IRELTEFAKSLPGFRNLDLNDQVTLLKYGVHEVIFTMLASLYN--KDGLLFPEGngyVTREFLESLRKPFCDIMEPKFEF 153

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 315 AGQLLPLEMDDTETGLLSAICLICGDRMDLEEPEKVDKLQEPLLEALRLYARRRRPSQPYMFPRMLMKITDLRGISTKGA 394
Cdd:cd06932  154 AEKFNALELTDSELALFCAVIILSPDRPGLINRKPVERIQEHVLQALELQLKKNHPDSPQLFAKLLQKMVDLRQLVTDHV 233

                        170       180
                 ....*....|....*....|.
gi 207028980 395 ERAITLKM-EIPGPMPPLIRE 414
Cdd:cd06932  234 QMVQQIKKtETDASLPPLLQE 254

DNA-binding domain of Farnesoid X receptor (FXR) family is composed of two C4-type zinc fingers; DNA-binding domain of Farnesoid X receptor (FXR) family is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. FXR interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. FXR is a member of the nuclear receptor family of ligand activated transcription factors. Bile acids are endogenous ligands for FXRs. Upon binding of a ligand, FXR binds to FXR response element (FXRE), which is an inverted repeat of TGACCT spaced by one nucleotide, either as a monomer or as a heterodimer with retinoid X receptor (RXR), to regulate the expression of various genes involved in bile acid, lipid, and glucose metabolism. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, FXR has a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 207028980  90 CFVCNDKSSGYHYGVSSCEGCKGFFRRSIQKNMVYTCHRDKNCIINKVTRNRCQYCRLQKCFEVGMSKE 158
Cdd:cd06962    4 CVVCGDKASGYHYNALTCEGCKGFFRRSITKNAVYKCKNGGNCEMDMYMRRKCQECRLRKCKEMGMLAE 72

The ligand binding domain of estrogen receptor and estrogen receptor-related receptors; The ligand binding domain of estrogen receptor (ER) and estrogen receptor-related receptors (ERRs): Estrogen receptors are a group of receptors which are activated by the hormone estrogen. Estrogen regulates many physiological processes including reproduction, bone integrity, cardiovascular health, and behavior. The main mechanism of action of the estrogen receptor is as a transcription factor by binding to the estrogen response element of target genes upon activation by estrogen and then recruiting coactivator proteins which are responsible for the transcription of target genes. Additionally some ERs may associate with other membrane proteins and can be rapidly activated by exposure of cells to estrogen. ERRs are closely related to the estrogen receptor (ER) family. But, it lacks the ability to bind estrogen. ERRs can interfere with the classic ER-mediated estrogen signaling pathway, positively or negatively. ERRs share target genes, co-regulators and promoters with the estrogen receptor (ER) family. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, ER and ERRs have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a non-conserved hinge and a C-terminal ligand binding domain (LBD).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 231 SELATKCIIKIVEFAKRLPGFTGLSIADQITLLKAACLDILMLRICTRYTPEQDTMTFSDGLTLNRTQMHNAGFGPLTDL 310
Cdd:cd07068   33 SDLADRELVHIISWAKHIPGFSDLSLNDQMHLLQSAWLEILMLGLVWRSLPHPGKLVFAPDLLLDREQARVEGLLEIFDM 112

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 207028980 311 VFAFAGQLLPLEMDDTETGLLSAICLICGDRMDLEEPEKVDKLQEPLLEALRLYARRRRPSQ-PYMFPRMLMKITDLRGI 389
Cdd:cd07068  113 LLQLVRRFRELGLQREEYVCLKAIILANSDVRHLEDREAVQQLRDAILDALVDVEAKRHGSQqPRRLAQLLLLLPHLRQA 192

                        170       180
                 ....*....|....*....|....*...
gi 207028980 390 STKGAERAITLKMEIPGPMPPLIREMLE 417
Cdd:cd07068  193 SNKGVRHLYSVKCEGKVPMYKLFLEMLE 220