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
                ....*....|....*....|....
gi 71983027   2 CRACRFTKCIAVGMRKSAVQRHRE 25
Cdd:cd06960  53 CRYCRFKKCLEVGMDPEAVQNERD 76

Ligand-binding domain of nuclear hormone receptor; This all helical domain is involved in binding the hormone in these receptors.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71983027    94 REPKAVAYTDAHNVHLKEIGLVADWIiKSYPDFEQLHQEQKKLLYRNFFLPFMILECGYMCCLNNRTDIlFLPSGDYIDC 173
Cdd:pfam00104   6 KKLRKATKEELCELWERDLLLVAEWA-KHFPEFQELPLEDQMALLKSFWLEWLRLEKAARSAKLRRKKI-LGEDVLMISD 83

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71983027   174 NRPETFYGHRIKSHLISPNEAVRMFGPSFEIYRRNVLDPMRRENVDNFEFFTLCSLVLWDHGLEGQTEECVQMARCNRER 253
Cdd:pfam00104  84 DDAMKFVEDDSSWCTNYDLEQLLFFLPFFNSYFFELVKPLRELNPDDEELAYLLAQLLFDYAGDGLSGEILEIVEKLQEK 163

                         170       180       190
                  ....*....|....*....|....*....|....*.
gi 71983027   254 ILREVLYYYRrvkqiSDPSMRLANLLVLLPALQRSV 289
Cdd:pfam00104 164 LANELHDYYV-----NKYSGRLAKLLKILPSLRKIS 194

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
                ....*....|....*....|....
gi 71983027   2 CRACRFTKCIAVGMRKSAVQRHRE 25
Cdd:cd06960  53 CRYCRFKKCLEVGMDPEAVQNERD 76

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
                  ....*....|....*
gi 71983027     2 CRACRFTKCIAVGMR 16
Cdd:pfam00105  54 CQYCRLKKCLEVGMS 68

Ligand-binding domain of nuclear hormone receptor; This all helical domain is involved in binding the hormone in these receptors.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71983027    94 REPKAVAYTDAHNVHLKEIGLVADWIiKSYPDFEQLHQEQKKLLYRNFFLPFMILECGYMCCLNNRTDIlFLPSGDYIDC 173
Cdd:pfam00104   6 KKLRKATKEELCELWERDLLLVAEWA-KHFPEFQELPLEDQMALLKSFWLEWLRLEKAARSAKLRRKKI-LGEDVLMISD 83

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71983027   174 NRPETFYGHRIKSHLISPNEAVRMFGPSFEIYRRNVLDPMRRENVDNFEFFTLCSLVLWDHGLEGQTEECVQMARCNRER 253
Cdd:pfam00104  84 DDAMKFVEDDSSWCTNYDLEQLLFFLPFFNSYFFELVKPLRELNPDDEELAYLLAQLLFDYAGDGLSGEILEIVEKLQEK 163

                         170       180       190
                  ....*....|....*....|....*....|....*.
gi 71983027   254 ILREVLYYYRrvkqiSDPSMRLANLLVLLPALQRSV 289
Cdd:pfam00104 164 LANELHDYYV-----NKYSGRLAKLLKILPSLRKIS 194

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
                ....*....|....*....|....
gi 71983027   2 CRACRFTKCIAVGMRKSAVQRHRE 25
Cdd:cd06960  53 CRYCRFKKCLEVGMDPEAVQNERD 76

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
                ....*....|....*....|
gi 71983027   2 CRACRFTKCIAVGMRKSAVQ 21
Cdd:cd06916  53 CQACRLKKCLAVGMRKEAVR 72

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
                ....*....|....*....|...
gi 71983027   2 CRACRFTKCIAVGMRKSAVQRHR 24
Cdd:cd07163  63 CRACRLKKCFEVGMNKDAVQHER 85

The DNA-binding domain of the photoreceptor cell-specific nuclear receptor (PNR) nuclear receptor-like family; 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
                ....*....|....*....|
gi 71983027   2 CRACRFTKCIAVGMRKSAVQ 21
Cdd:cd07154  54 CQACRLKKCLEVSMNKDAVQ 73

The second DNA-binding domain (DBD) of the 2DBD nuclear receptor is composed of two C4-type zinc fingers; The second DNA-binding domain (DBD) of the 2DBD nuclear receptor (NR) 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. NRs interact with specific DNA sites upstream of the target gene and modulate the rate of transcriptional initiation. The proteins contain two DBDs in tandem, probably resulting from an ancient recombination event. The 2DBD-NRs are found only in flatworm species, mollusks and arthropods. Their biological function is unknown.

                        10        20
                ....*....|....*....|
gi 71983027   1 MCRACRFTKCIAVGMRKSAV 20
Cdd:cd07179  52 ACKSCRFRRCLAVGMSKTGS 71

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
                  ....*....|....*
gi 71983027     2 CRACRFTKCIAVGMR 16
Cdd:pfam00105  54 CQYCRLKKCLEVGMS 68

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
                ....*....|....*....|...
gi 71983027   2 CRACRFTKCIAVGMRKSAVQRHR 24
Cdd:cd06956  55 CQYCRYQKCLAMGMKREAVQEER 77

DNA-binding domain of chicken ovalbumin upstream promoter transcription factors (COUP-TFs) is composed of two C4-type zinc fingers; DNA-binding domain of chicken ovalbumin upstream promoter transcription factors (COUP-TFs) 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. COUP-TFs are orphan members of the steroid/thyroid hormone receptor superfamily. They are expressed in many tissues and are involved in the regulation of several important biological processes, such as neurogenesis, organogenesis, cell fate determination, and metabolic homeostasis. COUP-TFs homodimerize or heterodimerize with retinoid X receptor (RXR) and a few other nuclear receptors and bind to a variety of response elements that are composed of imperfect AGGTCA direct or inverted repeats with various spacings. COUP-TFs are generally considered to be repressors of transcription for other nuclear hormone receptors such as retinoic acid receptor (RAR), thyroid hormone receptor (TR), vitamin D receptor (VDR), peroxisome proliferator activated receptor (PPAR), and hepatocyte nuclear factor 4 (HNF4). Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, COUP-TFs 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
                ....*....|....*....|.
gi 71983027   2 CRACRFTKCIAVGMRKSAVQR 22
Cdd:cd06958  53 CQYCRLKKCLKVGMRREAVQR 73

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
                ....*....|....*....|...
gi 71983027   2 CRACRFTKCIAVGMRKSAVQRHR 24
Cdd:cd07171  58 CQACRLRKCYEVGMMKGGIRRER 80

DNA-binding domain of REV-ERB receptor-like is composed of two C4-type zinc fingers; DNA-binding domain of REV-ERB receptor- like 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. REV-ERB receptors 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. REV-ERB receptors bind as a monomer to a (A/G)GGTCA half-site with a 5' AT-rich extension or as a homodimer to a direct repeat 2 element (AGGTCA sequence with a 2-bp spacer), indicating functional diversity. When bound to the DNA, they recruit corepressors (NcoR/histone deacetylase 3) to the promoter, resulting in repression of the target genes. The porphyrin heme has been demonstrated to function as a ligand for REV-ERB receptor. 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
                ....*....|....*....|...
gi 71983027   2 CRACRFTKCIAVGMRKSAVQRHR 24
Cdd:cd07166  59 CQYCRFKKCLAVGMSRDAVRFGR 81