helix loop helix domain;

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                  ....*....|....*....|....*....|....*....|....
gi 1088451      8 AAKTRREKENGEFYELAKLLPlPSAITSQLDKASIIRLTTSYLK 51
Cdd:smart00353  3 RERRRRRKINEAFDELRSLLP-TLPKNKKLSKAEILRLAIEYIK 45

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain found in single-minded (SIM) family; The SIM family includes Drosophila melanogaster protein SIM and its homologs from vertebrates, single-minded homolog 1 (SIM1) and single-minded homolog 2 (SIM2). SIM is a nuclear bHLH-PAS transcription factor that functions as a master developmental regulator controlling midline development of the ventral nerve cord in Drosophila. SIM1, also termed Class E basic helix-loop-helix protein 14 (bHLHe14), is a bHLH-PAS transcription factor that may have pleiotropic effects during embryogenesis and in the adult. SIM2, also termed Class E basic helix-loop-helix protein 15 (bHLHe15), is a bHLH-PAS transcription factor that may be a master gene of central nervous system (CNS) development in cooperation with ARNT. It may have pleiotropic effects in the tissues expressed during development.

                       10        20        30        40        50
               ....*....|....*....|....*....|....*....|....*....|....*...
gi 1088451   1 MKEKSKNAAKTRREKENGEFYELAKLLPLPSAITSQLDKASIIRLTTSYLKMRAVFPE 58
Cdd:cd11434  1 MKEKSKNAARTRREKENAEFYELAKLLPLPSAITSQLDKASIIRLTTSYLKMRAVFPE 58

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain found in Drosophila melanogaster protein single-minded (SIM) and similar proteins; SIM is a nuclear bHLH-PAS transcription factor that functions as a master developmental regulator controlling midline development of the ventral nerve cord in Drosophila.

                       10        20        30        40        50
               ....*....|....*....|....*....|....*....|....*....|....*...
gi 1088451   1 MKEKSKNAAKTRREKENGEFYELAKLLPLPSAITSQLDKASIIRLTTSYLKMRAVFPE 58
Cdd:cd19740  1 MKEKSKNAARSRREKENAEFLELAKLLPLPAAITSQLDKASIIRLTTSYLKMRQVFPD 58

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain found in neuronal PAS domain-containing protein 3 (NPAS3) and similar proteins; NPAS3, also termed neuronal PAS3, or Basic-helix-loop-helix-PAS protein MOP6, or Class E basic helix-loop-helix protein 12 (bHLHe12), or member of PAS protein 6, or PAS domain-containing protein 6 (PASD6), is a bHLH-PAS brain-enriched transcription factor that is involved in central nervous system development and neurogenesis. It is a replicated genetic risk factor for psychiatric disorders. Human chromosomal rearrangements that affect NPAS3 normal expression are associated with schizophrenia and mental retardation.

                       10        20        30        40        50
               ....*....|....*....|....*....|....*....|....*....|..
gi 1088451   2 KEKSKNAAKTRREKENGEFYELAKLLPLPSAITSQLDKASIIRLTTSYLKMR 53
Cdd:cd19732  7 KEKSRDAARSRRGKENFEFYELAKLLPLPAAITSQLDKASIIRLTISYLKMR 58

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain found in neuronal PAS domain-containing proteins, NPAS1, NPAS3 and similar proteins; The family includes neuronal PAS domain proteins NPAS1 and NPAS3, both of which are master regulators of neuropsychiatric function. NPAS1, also termed neuronal PAS1, or Basic-helix-loop-helix-PAS protein MOP5, or Class E basic helix-loop-helix protein 11 (bHLHe11), or member of PAS protein 5, or PAS domain-containing protein 5 (PASD5), is a bHLH-PAS transcriptional repressor expressed in the central nervous system and involved in neuronal differentiation. It is active during late embryogenesis and postnatal development. NPAS3, also termed neuronal PAS3, or Basic-helix-loop-helix-PAS protein MOP6, or Class E basic helix-loop-helix protein 12 (bHLHe12), or member of PAS protein 6, or PAS domain-containing protein 6 (PASD6), is a bHLH-PAS brain-enriched transcription factor that is involved in central nervous system development and neurogenesis. It is a replicated genetic risk factor for psychiatric disorders. Human chromosomal rearrangements that affect NPAS3 normal expression are associated with schizophrenia and mental retardation.

                       10        20        30        40        50
               ....*....|....*....|....*....|....*....|....*....|..
gi 1088451   2 KEKSKNAAKTRREKENGEFYELAKLLPLPSAITSQLDKASIIRLTTSYLKMR 53
Cdd:cd11432  1 KEKSRNAARSRRGKENYEFYELAKLLPLPAAISSQLDKASIVRLTISYLKLR 52

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain family; bHLH-PAS domain has been found in a large group of bHLH transcription regulators that are involved in gene expression responding to environmental change and controlling aspects of neural development, including proteins from aryl hydrocarbon receptor nuclear translocator (ARNT) family, hypoxia-inducible factor (HIF) family, aryl hydrocarbon receptor (AhR) family, neuronal PAS domain-containing protein (NPAS) family, Circadian locomotor output cycles protein kaput (CLOCK)-like family, and single-minded (SIM) family. bHLH-PAS transcriptional regulatory factors have a bHLH DNA-binding domain followed by two PAS domains and a C-terminal activation or repression domain. bHLH-PAS family members can be divided into class I and class II based on their dimerization partner. bHLH-PAS class I factors include AhR, HIF and SIM. The best characterized bHLH-PAS Class II protein is the ubiquitous ARNT. Some members of bHLH-PAS family act as transcriptional coactivators (such as NCoA) that lack the ability to dimerize and bind DNA.

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               ....*....|....*....|....*....|....*....|....*....|....*
gi 1088451   2 KEKSKNAAKTRREKENGEFYELAKLLPLPSAITSQLDKASIIRLTTSYLKMRAVF 56
Cdd:cd11391  1 REKSREAAKKRRDKENAEISELASLLPLPPAVGSKLDKLSVLRLAVAYLRLKKFL 55

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain found in hypoxia-inducible factor 3-alpha (HIF3a) and similar proteins; HIF3a, also termed HIF-3-alpha, or HIF3-alpha, or endothelial PAS domain-containing protein 1 (EPAS-1), or Basic-helix-loop-helix-PAS protein MOP7, or Class E basic helix-loop-helix protein 17 (bHLHe17), or Member of PAS protein 7, or PAS domain-containing protein 7 (PASD7), or HIF3-alpha-1, or inhibitory PAS domain protein (IPAS), is a bHLH-PAS transcriptional regulator in adaptive response to low oxygen tension. It plays a role in the regulation of hypoxia-inducible gene expression.

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               ....*....|....*....|....*....|....*....|....*....|.
gi 1088451   2 KEKSKNAAKTRREKENGEFYELAKLLPLPSAITSQLDKASIIRLTTSYLKM 52
Cdd:cd19729  5 KEKSRDAARCRRSQETEVFYELAHTLPFPRGVSSHLDKASIMRLTISYLRM 55

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain found in the aryl hydrocarbon receptor (AhR) family; The AhR family includes AhR, AhR repressor (AhRR) and Drosophila melanogaster protein spineless. AhR, also termed Ah receptor, or Dioxin receptor (DR), or Class E basic helix-loop-helix protein 76 (bHLHe76), is the only member of bHLH-PAS transcription regulators that bind and be activated by small chemical ligands. It is activated by Dioxin to control the expression of certain genes to influence biological processes such as apoptosis, proliferation, cell growth and differentiation. To form active DNA binding complexes AhR dimerizes with a bHLH-PAS factor ARNT (Aryl hydrocarbon Nuclear Receptor Translocator). AhRR, also termed Class E basic helix-loop-helix protein 77 (bHLHe77), is a member of bHLH-PAS transcription factors that acts as a negative regulator of AhR, playing key roles in development and environmental sensing. AhRR functions by competing with AhR for its partner ARNT. AhRR-ARNT complexes are transcriptionally inactive. Spineless is a bHLH-PAS transcription factor that plays an important role in fly morphogenesis. It is both necessary and sufficient for the formation of the ommatidial mosaic.

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               ....*....|....*....|....*....|....*....|....*....|
gi 1088451   7 NAAKTRREKENGEFYELAKLLPLPSAITSQLDKASIIRLTTSYLKMRAVF 56
Cdd:cd19696  6 NPSKRHRDRLNSELDELASLLPFPEDVISKLDKLSVLRLSVSYLRTKNYF 55

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain found in aryl hydrocarbon receptor (AhR) and similar proteins; AhR, also termed Ah receptor, or Dioxin receptor (DR), or Class E basic helix-loop-helix protein 76 (bHLHe76), is the only member of bHLH-PAS transcription regulators that bind and be activated by small chemical ligands. It is activated by Dioxin to control the expression of certain genes to influence biological processes such as apoptosis, proliferation, cell growth and differentiation. To form active DNA binding complexes AhR dimerize with a bHLH-PAS factor ARNT (Aryl hydrocarbon Nuclear Receptor Translocator).

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               ....*....|....*....|....*....|....*....|....*....|
gi 1088451   7 NAAKTRREKENGEFYELAKLLPLPSAITSQLDKASIIRLTTSYLKMRAVF 56
Cdd:cd11436  7 NPSKRHRDRLNTELDRLASLLPFPQDVISKLDKLSVLRLSVSYLRAKSFF 56

helix loop helix domain;

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                  ....*....|....*....|....*....|....*....|....
gi 1088451      8 AAKTRREKENGEFYELAKLLPlPSAITSQLDKASIIRLTTSYLK 51
Cdd:smart00353  3 RERRRRRKINEAFDELRSLLP-TLPKNKKLSKAEILRLAIEYIK 45

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain found in aryl hydrocarbon receptor nuclear translocator (ARNT) family; The ARNT family of bHLH-PAS transcription regulators includes ARNT, ARNT-like proteins (ARNTL and ARNTL2), and Drosophila melanogaster protein cycle. They act as the heterodimeric partner for bHLH-PAS proteins such as aryl hydrocarbon receptor (AhR), hypoxia-inducible factor (HIF), and single-minded (SIM). These bHLH-PAS transcription complexes are involved in transcriptional responses to xenobiotic, hypoxia, and developmental pathways. Heterodimerization of bHLH-PAS proteins with ARNT is mediated by contacts between both the bHLH and the tandem PAS domains. ARNT use bHLH and/or PAS domains to interact with several transcriptional coactivators. It is required for activity of the aryl hydrocarbon (dioxin) receptor. ARNTL, also termed Basic-helix-loop-helix-PAS protein MOP3, or brain and muscle ARNT-like 1 (BMAL1), or Class E basic helix-loop-helix protein 5 (bHLHe5), or member of PAS protein 3, or PAS domain-containing protein 3 (PASD3), or bHLH-PAS protein JAP3, is a member of the bHLH-PAS transcription factor family that forms heterodimers with another bHLH-PAS protein, CLOCK (circadian locomotor output cycle kaput), which regulates circadian rhythm. ARNTL-CLOCK heterodimer complex activates transcription from E-box (CANNTG) elements found in the promoter of circadian responsive genes. ARNTL is highly homologous to ARNT. ARNTL2, also termed Basic-helix-loop-helix-PAS protein MOP9, or brain and muscle ARNT-like 2 (BMAL2), or CYCLE-like factor (CLIF), or Class E basic helix-loop-helix protein 6 (bHLHe6), or member of PAS protein 9, or PAS domain-containing protein 9 (PASD9), is a neuronal bHLH-PAS transcriptional factor, regulating cell cycle progression and preventing cell death, whose sustained expression might ensure brain neuron survival. It also plays important roles in tumor angiogenesis. Protein cycle, also termed brain and muscle ARNT-like 1 (BMAL1), or MOP3, is a putative bHLH-PAS transcription factor involved in the generation of biological rhythms in Drosophila. It activates cycling transcription of Period (PER) and Timeless (TIM) by binding to the E-box (5'-CACGTG-3') present in their promoters.

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               ....*....|....*....|....*....|....*....|..
gi 1088451  10 KTRREKENGEFYELAKLLPLPSAITSQLDKASIIRLTTSYLK 51
Cdd:cd11437 10 KRRRDKMNAYIQELSALVPACNAMSRKLDKLTVLRMAVQHLK 51

basic Helix Loop Helix (bHLH) domain superfamily; bHLH proteins are transcriptional regulators that are found in organisms from yeast to humans. Members of the bHLH superfamily have two highly conserved and functionally distinct regions. The basic part is at the amino end of the bHLH that may bind DNA to a consensus hexanucleotide sequence known as the E box (CANNTG). Different families of bHLH proteins recognize different E-box consensus sequences. At the carboxyl-terminal end of the region is the HLH region that interacts with other proteins to form homo- and heterodimers. bHLH proteins function as a diverse set of regulatory factors because they recognize different DNA sequences and dimerize with different proteins. The bHLH proteins can be divided to cell-type specific and widely expressed proteins. The cell-type specific members of bHLH superfamily are involved in cell-fate determination and act in neurogenesis, cardiogenesis, myogenesis, and hematopoiesis.

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               ....*....|....*....|....*....|....*....|.
gi 1088451  12 RREKENGEFYELAKLLPLPSAItSQLDKASIIRLTTSYLKM 52
Cdd:cd00083  4 RRDKINDAFEELKRLLPELPDS-KKLSKASILQKAVEYIRE 43

basic helix-loop-helix-orange (bHLH-O) domain found in hairy and enhancer of split (HES)-related repressor protein (HERP)-like family; The HERP-like family includes bHLH-O transcriptional regulators that are related to the Drosophila hairy and Enhancer-of-split proteins. They contain a basic helix-loop-helix (bHLH) domain with an invariant glycine residue in its basic region, an orange domain in the central region and YXXW sequence motif at its C-terminal region. HERP proteins (HEY1, HEY2 and HEYL) act as downstream effectors of Notch signaling. They are involved in cardiovascular development and have roles in somitogenesis, myogenesis and gliogenesis. Hairy and enhancer of split-related protein HELT is a transcriptional repressor expressed in the developing central nervous system. It binds preferentially to the canonical E box sequence 5'-CACGCG-3' and regulates neuronal differentiation and/or identity. Differentially expressed in chondrocytes proteins, DEC1 and DEC2, are widely expressed in both embryonic and adult tissues and have been implicated in apoptosis, cell proliferation, and circadian rhythms, as well as malignancy in various cancers. Drosophila melanogaster protein clockwork orange (Cwo) is also included in this family. It is involved in the regulation of Drosophila circadian rhythms. It functions as both an activator and a repressor of clock gene expression.

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               ....*....|....*....|....*....|....*....|....*....
gi 1088451   6 KNAAKTRREKENGEFYELAKLLP--LPSAITSQLDKASIIRLTTSYLKM 52
Cdd:cd11389  2 KVIEKRRRDRINESLAELRRLVPeaRKSKGSGKLEKAEILEMTLQHLKA 50

basic helix-loop-helix-orange (bHLH-O) domain found in hairy/enhancer-of-split related with YRPW motif-like protein (HEYL) and similar proteins; HEYL, also termed Class B basic helix-loop-helix protein 33 (bHLHb33), or hairy-related transcription factor 3 (HRT-3), is a bHLH-O transcriptional repressor that is strongly expressed in the presomitic mesoderm, the somites, the peripheral nervous system and smooth muscle of all arteries and is a downstream effector of the Notch and transforming growth factor-beta pathways. It promotes neuronal differentiation by activating proneural genes and inhibiting other hairy and enhancer of split (HES) and hairy/enhancer-of-split related with YRPW motif protein (HEY) proteins. HEYL also functions as a tumor suppressor involved in the progression of human cancers.

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               ....*....|....*....|....*....|....*....|....*
gi 1088451  10 KTRREKENGEFYELAKLLP--LPSAITSQLDKASIIRLTTSYLKM 52
Cdd:cd11447 18 KRRRDRINSSLSELRRLVPtaFEKQGSSKLEKAEILQMTVDHLKM 62