basic helix-loop-helix (bHLH) domain found in achaete-scute-like protein 2 (ASCL-2) and similar proteins; ASCL-2, also termed achaete-scute homolog 2 (ASH-2), or Class A basic helix-loop-helix protein 45 (bHLHa45), or mammalian achaete scute homolog 2 (Mash2), is a bHLH transcription factor that is involved in Schwann cell differentiation and control of proliferation in adult peripheral nerves.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 4885665   49 AAAVARRNERERNRVKLVNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLAEHDAV 112
Cdd:cd19743   1 AAAVERRNERERNRVKLVNLGFAALRQHVPQGGASKKMSKVETLRSAVEYIRALQRLLGEHDAE 64

basic helix-loop-helix (bHLH) domain found in achaete-scute-like protein 2 (ASCL-2) and similar proteins; ASCL-2, also termed achaete-scute homolog 2 (ASH-2), or Class A basic helix-loop-helix protein 45 (bHLHa45), or mammalian achaete scute homolog 2 (Mash2), is a bHLH transcription factor that is involved in Schwann cell differentiation and control of proliferation in adult peripheral nerves.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 4885665   49 AAAVARRNERERNRVKLVNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLAEHDAV 112
Cdd:cd19743   1 AAAVERRNERERNRVKLVNLGFAALRQHVPQGGASKKMSKVETLRSAVEYIRALQRLLGEHDAE 64

Helix-loop-helix DNA-binding domain;

                          10        20        30
                  ....*....|....*....|....*....|....*...
gi 4885665     66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQ 103
Cdd:pfam00010  16 INDAFDELRELLPTLPPDKKLSKAEILRLAIEYIKHLQ 53

basic helix-loop-helix (bHLH) domain found in achaete-scute-like protein 2 (ASCL-2) and similar proteins; ASCL-2, also termed achaete-scute homolog 2 (ASH-2), or Class A basic helix-loop-helix protein 45 (bHLHa45), or mammalian achaete scute homolog 2 (Mash2), is a bHLH transcription factor that is involved in Schwann cell differentiation and control of proliferation in adult peripheral nerves.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 4885665   49 AAAVARRNERERNRVKLVNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLAEHDAV 112
Cdd:cd19743   1 AAAVERRNERERNRVKLVNLGFAALRQHVPQGGASKKMSKVETLRSAVEYIRALQRLLGEHDAE 64

basic helix-loop-helix (bHLH) domain found in Drosophila melanogaster achaete-scute complex (AS-C) proteins, achaete-scute-like proteins, ASCL1-2, and similar proteins; This subfamily includes Drosophila melanogaster AS-C proteins and two ASCL family of transcription factors, ASCL-1 and ASCL-2. Drosophila melanogaster AS-C proteins includes lethal of scute (also known as achaete-scute complex protein T3 or AST3), scute (also known as achaete-scute complex protein T4 or AST4), achaete (also known as achaete-scute complex protein T5 or AST5), and asense (also known as achaete-scute complex protein T8 or AST8). They are involved in the determination of the neuronal precursors in the peripheral nervous system and the central nervous system, as well as in sex determination and dosage compensation. ASCL-1, also termed Class A basic helix-loop-helix protein 46 (bHLHa46), or achaete-scute homolog 1 (ASH-1), or mammalian achaete scute homolog 1 (Mash1), is expressed in subsets of neural progenitors in both the central and peripheral nervous system. It plays a key role in neuronal differentiation and specification in the nervous system. ASCL-2, also termed achaete-scute homolog 2 (ASH-2), or Class A basic helix-loop-helix protein 45 (bHLHa45), or mammalian achaete scute homolog 2 (Mash2), is involved in Schwann cell differentiation and control of proliferation in adult peripheral nerves.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 4885665   51 AVARRNERERNRVKLVNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd19723   1 AVARRNERERNRVKLVNLGFATLREHVPNGRANKKMSKVETLRSAVEYIRQLQQLL 56

tissue specific basic helix-loop-helix (bHLH-TS) domain family; Tissue specific bHLH domain family includes transcription regulators whose expression are restricted to certain tissues. They are involved in cell-fate determination and process in neurogenesis, cardiogenesis, myogenesis, and hematopoiesis and include proteins from myogenic regulatory factor (MRF) family, twist-related protein (TWIST) family, scleraxis-like family, heart- and neural crest derivatives-expressed protein (HAND) family, helix-loop-helix protein (HEN) family, musculin-like family, germline alpha (FIGLA) family, T-cell acute lymphocytic leukemia protein/ lymphoblastic leukemia-derived sequence (TAL/LYL) family, ovary, uterus and testis protein (OUT) family, mesoderm posterior protein (Mesp) family, muscle, intestine and stomach expression 1 (MIST-1) family, protein atonal homologs (ATOH) family, neurogenin (NGN) family, neurogenic differentiation factor (NeuroD) family, achaete-scute complex-like (ASCL) family, Fer3-like protein (FERD3L)-like family, and Oligodendrocyte lineage genes (OLIG) family of transcription factors.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....
gi 4885665   63 VKLVNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd11390  12 MHDLNDAFEALRKVLPTVPPDKKLSKIETLRLAINYIAALSDLL 55

helix loop helix domain;

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|...
gi 4885665      66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLAE 108
Cdd:smart00353  11 INEAFDELRSLLPTLPKNKKLSKAEILRLAIEYIKSLQEELQK 53

basic helix-loop-helix (bHLH) domain found in achaete-scute-like proteins, ASCL3-5, and similar proteins; This subfamily includes three ASCL family of transcription factors, ASCL-3, ASCL-4 and ASCL-5. ASCL-3, also termed Class A basic helix-loop-helix protein 42 (bHLHa42), or bHLH transcriptional regulator Sgn-1, or achaete-scute homolog 3 (ASH-3), is specifically localized in the duct cells of the salivary glands. It may act as transcriptional repressor that inhibits myogenesis. ASCL-4, also termed Class A basic helix-loop-helix protein 44 (bHLHa44), or achaete-scute homolog 4 (ASH-4), or Hash4, may be involved in skin development. ASCL-5, also termed Class A basic helix-loop-helix protein 47 (bHLHa47), or achaete-scute homolog 5 (ASH-5), is an uncharacterized bHLH transcription factor that is close related to ASCL-3 and ASCL-4.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*..
gi 4885665   60 RNRVKLVNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd19724  10 RQRVRCVNEGYARLRRHLPLENKDKRLSKVETLRAAIRYIKHLQELL 56

basic helix-loop-helix (bHLH) domain found in achaete-scute-like protein 4 (ASCL-4) and similar proteins; ASCL-4, also termed Class A basic helix-loop-helix protein 44 (bHLHa44), or achaete-scute homolog 4 (ASH-4), or Hash4, is a bHLH transcriptional regulator that may be involved in skin development.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*..
gi 4885665   60 RNRVKLVNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd19746  17 RQRVRCVNEGYARLREHLPQELADKRLSKVETLRAAIDYIKHLQELL 63

basic helix-loop-helix (bHLH) domain found in factor in the germline alpha (FIGLA) and similar proteins; FIGLA, also termed FIGalpha, or Class C basic helix-loop-helix protein 8 (bHLHc8), or folliculogenesis-specific basic helix-loop-helix protein, or transcription factor FIGa, is a germ-cell-specific bHLH transcription factor expressed abundantly in female and less so in male germ cells. It is essential for primordial follicle formation and expression of many genes required for folliculogenesis, fertilization and early embryonic survival. FIGLA knockout mice cannot form primordial follicles and lose oocytes rapidly after birth, whereas male gonads are unaffected.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....
gi 4885665   63 VKLVNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd11422  12 VRNLNSGFSKLRRIVPLIPRDRKPSKVDTLKGATEYIRLLQRIL 55

basic helix-loop-helix (bHLH) domain found in scleraxis, transcription factor 15 (TCF-15) and similar proteins; The family includes scleraxis and transcription factor 15 (TCF-15). Scleraxis, also termed SCX, or Class A basic helix-loop-helix protein 41 (bHLHa41), or Class A basic helix-loop-helix protein 48 (bHLHa48), is a bHLH transcription factor that is expressed in sclerotome limb bud cranial and body wall mesenchyme, pericardium and heart valves, ligaments and tendons. It is required for tendon formation ligaments, connective tissue, the diaphragm, and testis development. Scleraxis plays a central role in promoting fibroblast proliferation and matrix synthesis during the embryonic development of tendons. TCF-15, also termed Class A basic helix-loop-helix protein 40 (bHLHa40), or paraxis, or protein bHLH-EC2, is a bHLH transcription factor expressed in caudal lateral and paraxial mesoderm dermomyotome and sclerotome fore limb buds during embryo development. It may function as an early transcriptional regulator involved in the patterning of the mesoderm and in lineage determination of cell types derived from the mesoderm.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|.
gi 4885665   66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd11465  15 VNSAFTALRTLIPTEPADRKLSKIETLRLASSYISHLATVL 55

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.

                        10        20        30
                ....*....|....*....|....*....|....*....
gi 4885665   66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQR 104
Cdd:cd00083   8 INDAFEELKRLLPELPDSKKLSKASILQKAVEYIRELQS 46

basic helix-loop-helix (bHLH) domain found in neurogenic differentiation factor (NeuroD) family; The NeuroD family includes NeuroD1, NeuroD2, NeuroD4 and NeuroD6. NeuroD1, also termed Class A basic helix-loop-helix protein 3 (bHLHa3), is a neuronal bHLH transcription factor involved in the development and maintenance of the endocrine pancreas and neuronal elements. It acts as an essential regulator of glutamatergic neuronal differentiation. Loss of NeuroD1 causes ataxia, cerebellar hypoplasia, sensorineural deafness, and severe retinal dystrophy in mice. NeuroD2, also termed Class A basic helix-loop-helix protein 1 (bHLHa1), or NeuroD-related factor (NDRF), is a neuronal calcium-dependent bHLH transcription factor that induces neuronal differentiation and promotes neuronal survival. It plays a central role in thalamocortical synaptic maturation. NeuroD2 mediates calcium-dependent transcription activation by binding to E box-containing promoter. NeuroD4, also termed Class A basic helix-loop-helix protein 4 (bHLHa4), or protein atonal homolog 3 (ATH-3), or Atoh3, or Math-3, is a bHLH transcriptional activator that mediates neuronal differentiation. NeuroD6, also termed Class A basic helix-loop-helix protein 2 (bHLHa2), or protein atonal homolog 2 (ATH-2), or Atoh2, or Math2, or Nex1, is a neurogenic bHLH transcription factor involved in neuronal development, differentiation, and survival in Alzheimer's disease (AD) brains of both cohorts. It plays an integrative role in coordinating increase in mitochondrial mass with cytoskeletal remodeling, suggesting that it may act as a co-regulator of neuronal differentiation and energy metabolism.

                        10        20        30
                ....*....|....*....|....*....|....
gi 4885665   73 LRQHVPHGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd11427  22 LRKVVPCYSKTQKLSKIETLRLARNYIWALSEIL 55

basic helix-loop-helix (bHLH) domain found in protein atonal homolog 7 (ATOH7) and similar proteins; ATOH7, also termed Class A basic helix-loop-helix protein 13 (bHLHa13), or helix-loop-helix protein hATH-5 (hATH5), or Math5, is a bHLH transcription factor involved in the differentiation of retinal ganglion cells.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|...
gi 4885665   66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLAE 108
Cdd:cd19714  23 LNTAFDRLRKVVPQWGQDKKLSKYETLQMALSYIMALTRILAE 65

basic helix-loop-helix (bHLH) domain found in Drosophila melanogaster protein dimmed and similar proteins; Dimmed, also termed DIMM, is a bHLH transcription factor that regulates neurosecretory (NS) cell function and neuroendocrine cell fate in Drosophila.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|...
gi 4885665   66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLAE 108
Cdd:cd19712  16 LNDAFQGLREVIPHVNAERKLSKIETLTLAKNYIKALTNVICE 58

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in transcription factor AP-4 (TFAP4) and similar proteins; TFAP4, also termed activating enhancer-binding protein 4, or Class C basic helix-loop-helix protein 41 (bHLHc41), is a bHLHzip transcription factor that activates both viral and cellular genes involved in the regulation of cellular proliferation, stemness, and epithelial-mesenchymal transition by binding to the symmetrical DNA sequence 5'-CAGCTG-3'.

                        10        20        30
                ....*....|....*....|....*....|....*....
gi 4885665   66 VNLGFQALRQHVPHgGASKKLSKVETLRSAVEYIRALQR 104
Cdd:cd11419  19 INAGFQSLRTLLPH-CDGEKLSKAAILQQTAEYIFSLEQ 56

basic helix-loop-helix (bHLH) domain found in Drosophila melanogaster protein taxi and similar proteins; Protein taxi, also termed protein delilah (Dei), is a bHLH transcription factor that is involved in regulation of cell adhesion and attachment that is expressed in specialized cells that provide anchoring sites to either muscles (tendon cells), or proprioceptors (chordotonal attachment cells) during embryonic development. It probably plays an important role in the differentiation of epidermal cells into the tendon cells that form the attachment sites for all muscles.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....
gi 4885665   66 VNLGFQALRQHVP---HGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd11431  16 INDAFEALRRAVPeypVAGKDGKLTKITTLRLAMNYIKALTDLL 59

basic helix-loop-helix (bHLH) domain found in heart- and neural crest derivatives-expressed protein (HAND) family; The HAND family includes two bHLH transcription factors, HAND1 and HAND2. HAND1, also termed Class A basic helix-loop-helix protein 27 (bHLHa27), or extraembryonic tissues, heart, autonomic nervous system and neural crest derivatives-expressed protein 1 (eHAND), plays an essential role in both trophoblast-giant cells differentiation and in cardiac morphogenesis. HAND2, also termed Class A basic helix-loop-helix protein 26 (bHLHa26), or deciduum, heart, autonomic nervous system and neural crest derivatives-expressed protein 2 (dHAND), is essential for cardiac morphogenesis, particularly for the formation of the right ventricle and of the aortic arch arteries.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|.
gi 4885665   66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd11466  16 INSAFADLRECIPNVPADTKLSKIKTLRLATSYIAYLMDVL 56

basic helix-loop-helix (bHLH) domain found in Caenorhabditis elegans Helix-loop-helix protein 13 (HLH13) and similar proteins; Caenorhabditis elegans HLH13, also termed Fer3-like protein, or nephew of atonal 3, is a bHLH transcription factor that plays a role in the negative regulation of exit from L1 arrest and dauer diapause dependent on IIS signaling (insulin and insulin-like growth factor (IGF) signaling).

                        10        20        30        40
                ....*....|....*....|....*....|....*....|.
gi 4885665   66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd11416  20 INSAFEELRCHVPTFPYEKRLSKIDTLRLAIAYIALLRDIL 60

basic helix-loop-helix (bHLH) domain found in Drosophila melanogaster myogenic-determination protein (dMYOD) and similar proteins; dMYOD, also termed protein nautilus, or Myd, may play an important role in the early development of muscle in Drosophila.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....
gi 4885665   63 VKLVNLGFQALRQHVPhGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd19699  14 LRKVNEAFEVLKRRTC-PNPNQRLPKVEILRNAIEYIESLEDLL 56

basic helix-loop-helix (bHLH) domain found in T-cell acute lymphocytic leukemia protein 1 (TAL-1) and similar proteins; TAL-1, also termed Class A basic helix-loop-helix protein 17 (bHLHa17), or stem cell protein (SCL), or T-cell leukemia/lymphoma protein 5, is a hematopoietic-specific bHLH transcription factor that functions in embryonic and adult hematopoiesis in vertebrates. It is also required for embryonic vascular remodeling. It acts as a regulator of erythroid differentiation and binds to regulatory regions of a large cohort of erythroid genes as part of a complex with GATA-1, LMO2 and Ldb1. TAL-1 has been implicated in T-cell acute lymphoblastic leukemia. In common with other tissue-specific bHLH proteins, Tal heterodimerizes with ubiquitously-expressed members of the E2A family and form a DNA-binding complex with an E-box (CANNTG) to regulate transcription at its recognition site.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*
gi 4885665   66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLAEHD 110
Cdd:cd19706  19 VNGAFAELRKLIPTHPPDKKLSKNEILRLAMKYINFLAKLLNDQE 63

basic helix-loop-helix (bHLH) domain found in protein atonal homolog 8 (ATOH8) and similar proteins; ATOH8, also termed Class A basic helix-loop-helix protein 21 (bHLHa21), or helix-loop-helix protein hATH-6 (hATH6), is a bHLH shear-stress-responsive transcription factor expressed in activated satellite cells and proliferating myoblasts of human skeletal muscle tissue. It regulates endothelial cell proliferation, migration and tube-like structures formation. ATOH8 binds a palindromic (canonical) core consensus DNA sequence 5'-CANNTG- 3' known as an E-box element, possibly as a heterodimer with other bHLH proteins.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*..
gi 4885665   62 RVKLVNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLAE 108
Cdd:cd11421  19 RVHTISAAFEALRKAVPSYSYNQKLSKLAILRIACSYILALARLADL 65

basic helix-loop-helix (bHLH) domain found in Drosophila melanogaster protein Amos and similar proteins; Amos, also termed absent MD neurons and olfactory sensilla protein, or reduced olfactory organs protein, or rough eye protein, is a bHLH transcription factor that promotes multiple dendritic neuron formation in the Drosophila peripheral nervous system.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|.
gi 4885665   66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd19715  23 LNVAFDKLRDVVPSLGDDRKLSKYETLQMAQSYITALKELL 63

basic helix-loop-helix (bHLH) domain found in muscle-specific regulatory factor 4 (MRF4) and similar proteins; MRF4, also termed Class C basic helix-loop-helix protein 4 (bHLHc4), or myogenic factor 6 (Myf-6), is a bHLH transcription factor associated with myogenesis. It plays a role in skeletal muscle differentiation.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*....
gi 4885665   63 VKLVNLGFQAL-RQHVPHggASKKLSKVETLRSAVEYIRALQRLLAEHD 110
Cdd:cd18934  14 LKKINEAFEALkRRTVPN--PNQRLPKVEILRSAINYIEKLQDLLHSLD 60

basic helix-loop-helix (bHLH) domain found in myogenin (MYOG) and similar proteins; MYOG, also termed Class C basic helix-loop-helix protein 3 (bHLHc3), or myogenic factor 4 (Myf-4), is a bHLH transcriptional activator that promotes transcription of muscle-specific target genes and plays a role in muscle differentiation, cell cycle exit and muscle atrophy.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*
gi 4885665   63 VKLVNLGFQALRQHVPHGgASKKLSKVETLRSAVEYIRALQRLLA 107
Cdd:cd18935  14 LKKVNEAFEALKRSTLLN-PNQRLPKVEILRSAIQYIERLQALLS 57

basic helix-loop-helix (bHLH) domain found in helix-loop-helix protein 1 (HEN-1) and similar proteins; HEN-1, also termed nescient helix-loop-helix 1 (Nhlh1), or Class A basic helix-loop-helix protein 35 (bHLHa35), or nescient helix loop helix 1 (NSCL-1), is a neuron-specific bHLH transcription factor that may serve as DNA-binding protein and may be involved in the control of cell-type determination, possibly within the developing nervous system.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 4885665   36 RRRRPATAETGGGAAAvarrneRERNRVKLVNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd19701   7 RRRRRATAKYRTAHAT------RERIRVEAFNVAFAELRKLLPTLPPDKKLSKIEILRLAICYISYLNHVL 71

basic helix-loop-helix (bHLH) domain found in scleraxis and similar proteins; Scleraxis, also termed SCX, or Class A basic helix-loop-helix protein 41 (bHLHa41), or Class A basic helix-loop-helix protein 48 (bHLHa48), is a bHLH transcription factor that is expressed in sclerotome limb bud cranial and body wall mesenchyme, pericardium and heart valves, ligaments and tendons. It is required for tendon formation ligaments, connective tissue, the diaphragm, and testis development. Scleraxis plays a central role in promoting fibroblast proliferation and matrix synthesis during the embryonic development of tendons.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*.
gi 4885665   66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLAEHDA 111
Cdd:cd18951  19 VNTAFTALRTLIPTEPADRKLSKIETLRLASSYISHLGNVLLVGEA 64

basic helix-loop-helix (bHLH) domain found in protein lyl-1 and similar proteins; Lyl-1, also termed Class A basic helix-loop-helix protein 18 (bHLHa18), or lymphoblastic leukemia-derived sequence 1, is a proto-oncogenic bHLH transcription factor involved in T-cell acute lymphoblastic leukemia. It plays an important role in hematopoietic stem cell function and is required for the late stages of postnatal angiogenesis to limit the formation of new blood vessels, notably by regulating the activity of the small GTPase Rap1. LYL-1 deficiency induces a stress erythropoiesis.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....
gi 4885665   66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLAEH 109
Cdd:cd19705  21 VNGAFAELRKLIPTHPPDKKLSKNEILRLAMKYIDFLVTLLRDQ 64

basic helix-loop-helix (bHLH) domain found in DNA-binding protein inhibitor ID4 and similar proteins; ID4, also termed Class B basic helix-loop-helix protein 27 (bHLHb27), or inhibitor of DNA binding 4, or inhibitor of differentiation 4, is a dominant negative helix-loop-helix (dnHLH) transcriptional regulator (lacking a basic DNA binding domain) which negatively regulates the bHLH transcription factors by forming heterodimers and inhibiting their DNA binding and transcriptional activity. It plays a role in adipose cell differentiation.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*..
gi 4885665   66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLAEHDAV 112
Cdd:cd19694  11 MNDCYSRLKRLVPTIPPNKKVSKVEILQHVIDYILDLQLALETHPAL 57

basic helix-loop-helix (bHLH) domain found in myogenic factor 5 (Myf-5) and similar proteins; Myf-5, also termed Class C basic helix-loop-helix protein 2 (bHLHc2), is a nuclear bHLH transcriptional activator that promotes transcription of muscle-specific target genes and plays a role in muscle specification and differentiation. It also acts as an RNA-binding protein which enhances Ccnd1/Cyclin D1 mRNA translation during myogenesis.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*..
gi 4885665   63 VKLVNLGFQALRQhVPHGGASKKLSKVETLRSAVEYIRALQRLLAEH 109
Cdd:cd18937  14 LKKVNQAFETLKR-CTTSNPNQRLPKVEILRNAIRYIESLQDLLREQ 59

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in MLX-interacting protein (MLXIP), MLX-interacting protein-like (MLXIPL) and similar proteins; The family includes MLXIP and MLXIPL. MLXIP, also termed Class E basic helix-loop-helix protein 36 (bHLHe36), or transcriptional activator MondoA, is a bHLHZip transcriptional activator that binds DNA as a heterodimer with Mlx. It binds to the canonical E box sequence 5'-CACGTG-3' and plays a role in transcriptional activation of glycolytic target genes. MLXIP is most highly expressed in skeletal muscle and functions as an indirect glucose sensor, by sensing glucose 6-phosphate and shuttling between the nucleus and the cytoplasm. MLXIPL, also termed carbohydrate-responsive element-binding protein (ChREBP), or Class D basic helix-loop-helix protein 14 (bHLHd14), or MLX interactor, or WS basic-helix-loop-helix leucine zipper protein (WS-bHLH), or Williams-Beuren syndrome chromosomal region 14 protein (WBSCR14), is a bHLHZip transcriptional factor integral to the regulation of glycolysis and lipogenesis in the liver. It forms heterodimers with the bHLHZip protein Mlx to bind the DNA sequence 5'-CACGTG-3'.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|.
gi 4885665   66 VNLGFQALRQHVPHGGA--SKKLSKVETLRSAVEYIRALQR 104
Cdd:cd11405  18 IKSGFDTLQSLIPSLGQnpNQKVSKAAMLQKAAEYIKSLKR 58

basic helix-loop-helix (bHLH) domain found in neurogenin-2 (NGN-2) and similar proteins; NGN-2, also termed Class A basic helix-loop-helix protein 8 (bHLHa8), or protein atonal homolog 4 (ATOH4), is a neural-specific bHLH transcription factor required for sensory neurogenesis. It activates transcription by binding to the E box (5'-CANNTG-3').

                        10        20        30        40
                ....*....|....*....|....*....|....*....|.
gi 4885665   66 VNLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLL 106
Cdd:cd19717  25 LNAALDSLREVLPTFPEDAKLTKIETLRFAHNYIWALSETL 65

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in N-Myc and similar proteins; N-Myc, also termed Class E basic helix-loop-helix protein 37 (bHLHe37), is a bHLHZip proto-oncogene protein that positively regulates the transcription of MYCNOS in neuroblastoma cells. It is also essential during embryonic development. N-Myc has a critical role in regulating the switch between proliferation and differentiation of progenitor cells. It binds DNA as a heterodimer with MAX. The family also includes S-Myc, encoded by rat or mouse intronless myc gene, which has apoptosis-inducing activity.

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                ....*....|....*....|....*....|....*....|....*
gi 4885665   70 FQALRQHVPHGGASKKLSKVETLRSAVEYIRALQ----RLLAEHD 110
Cdd:cd11456  24 FLTLRDHVPELVKNEKAAKVVILKKATEYVHSLQaeeqKLLLEKE 68

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in sterol regulatory element-binding protein (SREBP) family; The SREBP family includes SREBP1 and SREBP2, which are bHLHzip transcriptional activator of genes encoding proteins essential for cholesterol biosynthesis/uptake and fatty acid biosynthesis. SREBP1 and SREBP2 are principally found in the liver and in adipocytes and made up of an N-terminal transcription factor portion (composed of an activation domain, a bHLHzip domain, and a nuclear localization signal), a hydrophobic region containing two membrane spanning regions, and a C-terminal regulatory segment. They recognize a symmetric sterol regulatory element (TCACNCCAC) instead of E-box.

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                ....*....|....*....|....*....|....*....|
gi 4885665   81 GASKKLSKVETLRSAVEYIRALQ----RLLAEHDAVRNAL 116
Cdd:cd11394  34 GPDAKMNKSAVLRKAIDYIRYLQkvnqKLKQENMALKKAL 73

basic helix-loop-helix (bHLH) domain found in neurogenin (NGN) family; The NGN family includes three neural-specific bHLH transcription factors, NGN1-3, which may function at neuroblast selection genes during the development of several neuronal lineages. NGN-1, also termed Class A basic helix-loop-helix protein 6 (bHLHa6), or neurogenic basic-helix-loop-helix protein, or neurogenic differentiation factor 3 (NeuroD3), is a neural-specific bHLH transcription factor involved in the initiation of neuronal differentiation. NGN-2, also termed Class A basic helix-loop-helix protein 8 (bHLHa8), or protein atonal homolog 4 (ATOH4), is a neural-specific bHLH transcription factor required for sensory neurogenesis. NGN-3, also termed Class A basic helix-loop-helix protein 7 (bHLHa7), or protein atonal homolog 5 (ATOH5), is a neural-specific bHLH transcription factor expressed in the developing central nervous system and the embryonic pancreas. It is involved in neurogenesis and plays an important role in spermatogenesis.

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                ....*....|....*....|....*....|....*....|.
gi 4885665   67 NLGFQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLA 107
Cdd:cd11428  17 NDALDALREVLPSFPDETKLTKIETLRFAHNYIWALSETLK 57

basic helix-loop-helix (bHLH) domain found in Drosophila melanogaster protein extra-macrochaetae and similar proteins; Extra-macrochaetae is a negative regulator of sensory organ development in Drosophila. It belongs to dominant negative group of helix-loop-helix (dnHLH) proteins, which lack a basic DNA-binding domain but can form heterodimers with other HLH proteins, thereby inhibiting DNA binding.

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                ....*....|....*....|....*....|....*....|
gi 4885665   70 FQALRQHVPHGGASKKLSKVETLRSAVEYIRALQRLLAEH 109
Cdd:cd19695  12 LAKLRNLVPTLPKNRKVSKLELLQHVIDYIADLEEQLEDH 51