Helix-loop-helix DNA-binding domain;

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 31317299    67 YDMNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQ 106
Cdd:pfam00010  14 DRINDAFDELRELLPTLPPDKKLSKAEILRLAIEYIKHLQ 53

basic helix-loop-helix (bHLH) domain found in the DNA-binding protein inhibitor (ID) family; The ID family includes a dominant negative group of helix-loop-helix (dnHLH) proteins, ID1-4, that are negative regulators of bHLH transcription factors. They contain the HLH-dimerization domain but lack the basic domain necessary for DNA-binding. ID proteins inhibit binding to DNA and transcriptional transactivation by heterodimerization with bHLH proteins. They also interact with many non-bHLH proteins in complex networks. ID proteins have been implicated in regulating gene expression as well as cell-cycle progression. Whereas ID-1, ID-2 and ID-3, are generally considered as tumor promoters, ID4 on the contrary has emerged as a tumor suppressor.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*.
gi 31317299  63 NVLLYDMNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLE 108
Cdd:cd19684   2 DILNAEMQDCYSKLKELVPTIPQNKKVSKVEILQHVIDYILDLQLA 47

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        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 31317299  59 EQQVNVLLYDMNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLELNS 111
Cdd:cd19694   1 EEEALCLQYDMNDCYSRLKRLVPTIPPNKKVSKVEILQHVIDYILDLQLALET 53

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.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*
gi 31317299  57 LDEQQVNVLLYdmngcYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLELNS 111
Cdd:cd19695   1 LNQERREMALY-----LAKLRNLVPTLPKNRKVSKLELLQHVIDYIADLEEQLED 50

helix loop helix domain;

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|..
gi 31317299     68 DMNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLEL 109
Cdd:smart00353  10 KINEAFDELRSLLPTLPKNKKLSKAEILRLAIEYIKSLQEEL 51

basic helix-loop-helix (bHLH) domain found in achaete-scute complex-like (ASCL) family; The achaete-scute complex-like (ASCL, also known as achaete-scute complex homolog or ASH) family of bHLH transcription factors, ASCL1-5, have been implicated in cell fate specification and differentiation. They are critical for proper development of the nervous system. The deregulation of ASCL plays a key role in psychiatric and neurological disorders. 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 a neural-specific bHLH transcription factor that 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 a bHLH transcription factor that is involved in Schwann cell differentiation and control of proliferation in adult peripheral nerves. 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 a bHLH transcription factor specifically localized in the duct cells of the salivary glands. It may act as transcriptional repressor that inhibits myogenesis. The family also includes Drosophila melanogaster achaete-scute complex (AS-C) proteins, which consists of 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.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|
gi 31317299  70 NGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLEL 109
Cdd:cd11418  17 NDAFDRLRQHVPYLKRRKKLSKVKTLRRAIEYIRHLQKLL 56

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana paclobutrazol resistance (PRE) family; The PRE family includes several bHLH transcription factors from Arabidopsis thaliana, such as PRE1-6. PRE1 (also termed AtbHLH136, or protein banquo 1), PRE2 (also termed AtbHLH134, or protein banquo 2, or EN 52), PRE4 (also termed AtbHLH161, or protein banquo 3), and PRE5 (also termed AtbHLH164) are atypical and probable non DNA-binding bHLH transcription factors that integrate multiple signaling pathways to regulate cell elongation and plant development. PRE3 (also termed AtbHLH135, or protein activation-tagged BRI1 suppressor 1, or ATBS1, or protein target of MOOPTEROS 7, or EN 67) is an atypical and probable non DNA-binding bHLH transcription factor required for MONOPTEROS-dependent root initiation in embryo. It promotes the correct definition of the hypophysis cell division plane. PRE5 (also termed AtbHLH163, or protein KIDARI) is an atypical and probable non DNA-binding bHLH transcription factor that regulates light-mediated responses in day light conditions by binding and inhibiting the activity of the bHLH transcription factor HFR1, a critical regulator of light signaling and shade avoidance.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*.
gi 31317299  69 MNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLELNSESE 114
Cdd:cd11442  12 KNDLYSRLRALLPSIATSDKVSKATVLEEACNYIRNLHREVDDLSE 57

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
                ....*....|....*....|....*....|....*....|
gi 31317299  70 NGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLEL 109
Cdd:cd19723  17 NLGFATLREHVPNGRANKKMSKVETLRSAVEYIRQLQQLL 56

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in the Myc family; The Myc family is a member of the bHLHzip family of transcription factors that play important roles in the control of normal cell proliferation, growth, survival and differentiation. All Myc isoforms contain two independently functioning polypeptide chain regions: N-terminal transactivating residues and a C-terminal bHLHzip segment. The bHLHzip family of bHLH transcription factors are characterized by a highly conserved N-terminal basic region that may bind DNA at a consensus hexanucleotide sequence known as the E-box (CANNTG) followed by HLH and leucine zipper motifs that may interact with other proteins to form homo- and heterodimers. Myc heterodimerizes with Max enabling specific binding to E-box DNA sequences in the promoters of target genes. The Myc proto-oncoprotein family includes at least five different functional members: c-, N-, L-, S- and B-Myc (which is lacking the bHLH domain).

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|
gi 31317299  68 DMNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQ---LELNSESE 114
Cdd:cd11400  15 DLKNSFEKLRDLVPELADNEKASKVVILKKATEYIKQLQqeeKKLEKEKD 64

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 31317299  68 DMNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLELNSESE 114
Cdd:cd19706  18 NVNGAFAELRKLIPTHPPDKKLSKNEILRLAMKYINFLAKLLNDQEE 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 31317299  68 DMNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLELNSES 113
Cdd:cd19705  20 NVNGAFAELRKLIPTHPPDKKLSKNEILRLAMKYIDFLVTLLRDQA 65

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in Max-like protein X (Mlx) family; Mlx, also termed Class D basic helix-loop-helix protein 13 (bHLHd13), or Max-like bHLHZip protein, or protein BigMax, or transcription factor-like protein 4, is a Max-like bHLHZip transcription regulator that interacts with the Max network of transcription factors. It forms a sequence-specific DNA-binding protein complex with some member of Mad family (Mad1 and Mad4) and Mondo family but not the Myc family and bind the E-box DNA to control transcription. The family also includes Saccharomyces cerevisiae INO4, which is a bHLH transcriptional activator of phospholipid synthetic genes (such as INO1, CHO1/PSS, CHO2/PEM1, OPI3/PEM2, etc.). It is required for de-repression of phospholipid biosynthetic gene expression in response to inositol deprivation in yeast.

                        10        20        30
                ....*....|....*....|....*....|....*...
gi 31317299  69 MNGCYSRLKELVPTLpQNRKVSKVEILQHVIDYIRDLQ 106
Cdd:cd11404  17 IKKGYDELCALVPGL-DPQKRTKADILQKAADWIQELK 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
                ....*....|....*....|....*....|....*..
gi 31317299  70 NGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQ 106
Cdd:cd19724  17 NEGYARLRRHLPLENKDKRLSKVETLRAAIRYIKHLQ 53

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
                ....*....|....*....|....*....|...
gi 31317299  70 NGCYSRLKELVPTLPQNRKVSKVEILQHVIDYI 102
Cdd:cd19701  32 NVAFAELRKLLPTLPPDKKLSKIEILRLAICYI 64

basic helix-loop-helix (bHLH) domain found in Fer3-like protein (FERD3L), pancreas transcription factor 1 subunit alpha (PTF1A) and similar proteins; The family corresponds to a group of bHLH transcription factors, including FERD3L and PTF1A. FERD3L, also termed basic helix-loop-helix protein N-twist, or Class A basic helix-loop-helix protein 31 (bHLHa31), or nephew of atonal 3 (NATO3), or Neuronal twist (NTWIST), is expressed in the developing central nervous system (CNS). It regulates floor plate (FP) cells development. FP is a critical organizing center located at the ventral-most midline of the neural tube. FERD3L binds to the E-box and functions as inhibitor of transcription. PTF1A, also termed Class A basic helix-loop-helix protein 29 (bHLHa29), or pancreas-specific transcription factor 1a, or bHLH transcription factor p48, or p48 DNA-binding subunit of transcription factor PTF1 (PTF1-p48), is implicated in the cell fate determination in various organs. It binds to the E-box consensus sequence 5'-CANNTG-3' and plays a role in early and late pancreas development and differentiation.

                        10        20        30
                ....*....|....*....|....*....|....*..
gi 31317299  69 MNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDL 105
Cdd:cd19686  16 INDAFDGLRRHIPTFPYEKRLSKVDTLRLAIQYINFL 52

basic helix-loop-helix (bHLH) domain found in protein atonal homologs ATOH1, ATOH7 and similar proteins; The family includes ATOH1 and ATOH7. ATOH1, also termed Class A basic helix-loop-helix protein 14 (bHLHa14), or helix-loop-helix protein hATH-1 (hATH1), or Math1, or Cath1, is a proneural bHLH transcription factor that is essential for inner ear hair cell differentiation. It dimerizes with E47 and activates E-box (CANNTG) dependent transcription. ATOH1 is a mammalian homolog of the Drosophila melanogaster gene atonal and mouse atonal homolog 1 (Math1). 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. The family also includes protein Amos (also termed absent MD neurons and olfactory sensilla protein, or reduced olfactory organs protein, or rough eye protein). It is a bHLH transcription factor that promotes multiple dendritic neuron formation in the Drosophila peripheral nervous system.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....
gi 31317299  66 LYDMNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLEL 109
Cdd:cd11430  13 MNGLNRAFDQLRSVVPSIGNDKKLSKYETLQMAQIYIETLSELL 56

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
                ....*....|....*....|....*....|....*....|...
gi 31317299  73 YSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLELNSESEV 115
Cdd:cd19743  22 FAALRQHVPQGGASKKMSKVETLRSAVEYIRALQRLLGEHDAE 64

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
                ....*....|....*....|....*....|....*..
gi 31317299  69 MNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDL 105
Cdd:cd19714  23 LNTAFDRLRKVVPQWGQDKKLSKYETLQMALSYIMAL 59

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
                ....*....|....*....|....*....|....*..
gi 31317299  66 LYDMNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYI 102
Cdd:cd19717  22 MHNLNAALDSLREVLPTFPEDAKLTKIETLRFAHNYI 58

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in Max-binding protein Mnt and similar proteins; Mnt, also termed Class D basic helix-loop-helix protein 3 (bHLHd3), or Myc antagonist MNT, or protein ROX, is a bHLHZip transcriptional repressor that binds DNA as a heterodimer with MAX. It binds to the canonical E box sequence 5'-CACGTG-3' and, with higher affinity, to 5'-CACGCG-3'. Mnt has an important role as an antagonist and regulator of Myc activities and it is a potential tumor suppressor. Mnt is ubiquitously expressed. Mnt-deficient mice shown to exhibit early postnatal lethality.

                        10        20        30
                ....*....|....*....|....*....|....*
gi 31317299  72 CYSRLKELVPTLpQNRKVSKVEILQHVIDYIRDLQ 106
Cdd:cd11402  20 CFETLKRQIPNL-DDKKTSNLNILRSALRYIQILK 53

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.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 31317299  56 LLDEQQVNvllyDMNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLE 108
Cdd:cd11456  11 ILERQRRN----DLRSSFLTLRDHVPELVKNEKAAKVVILKKATEYVHSLQAE 59

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in sterol regulatory element-binding protein (SREBP) family and similar proteins; 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. The family also includes Saccharomyces cerevisiae transcription factor HMS1 (also termed high-copy MEP suppressor protein 1) and serine-rich protein TYE7. HMS1 is a putative bHLHzip transcription factor involved in exit from mitosis and pseudohyphal differentiation. TYE7, also termed basic-helix-loop-helix protein SGC1, is a putative bHLHzip transcription activator required for Ty1-mediated glycolytic gene expression. TYE7 N-terminal is extremely rich in serine residues. It binds DNA on E-box motifs, 5'-CANNTG-3'. TYE7 is not essential for growth.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 31317299  69 MNGCYSRLKELVPTLPQN---------------RKVSKVEILQHVIDYIRDLQ 106
Cdd:cd11395  18 LNTKIERLRDAIPSLRSPegksddgglgglaptTKLSKATILTKAIEYIRHLE 70

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 31317299  67 YDMNGCYSRLKELVPTL--PQNRKVSKVEILQHVIDYIRDLQLE 108
Cdd:cd11405  16 FNIKSGFDTLQSLIPSLgqNPNQKVSKAAMLQKAAEYIKSLKRE 59

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in protein Max and similar proteins; Max, also termed Class D basic helix-loop-helix protein 4 (bHLHd4), or Myc-associated factor X, is a bHLHZip transcription regulator that forms a sequence-specific DNA-binding protein complex with MYC or MAD which recognizes the core sequence 5'-CAC[GA]TG-3'. The MYC:MAX complex is a transcriptional activator, whereas the MAD:MAX complex is a transcriptional repressor. Max homodimer bind DNA but is transcriptionally inactive. Targeted deletion of max results in early embryonic lethality in mice.

                        10        20        30
                ....*....|....*....|....*....|....*.
gi 31317299  71 GCYSRLKELVPTLpQNRKVSKVEILQHVIDYIRDLQ 106
Cdd:cd11406  18 DSFHSLRDSVPSL-QGEKASRAQILKKATEYIQYMR 52

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in Schizosaccharomyces pombe ESC1 (spESC1) and similar proteins; spESC1 is a bHLHzip protein with homology to human MyoD and Myf-5 myogenic differentiation inducers. It is involved in the sexual differentiation process.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 31317299  68 DMNGCYSRLKELvptLPQNR--KVSKVEILQHVIDYI-------RDLQLELNS 111
Cdd:cd19690  14 EMKELFEDLRDA---LPQERgtKASKWEILTKAISYIqqlkrhiRELRSEVND 63

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana phytochrome interacting factors (PIFs) and similar proteins; The family includes several bHLH transcription factors from Arabidopsis thaliana, such as PIFs, ALC, PIL1, SPATULA, and UNE10. PIFs (PIF1, PIF3, PIF4, PIF5, PIF6 and PIF7) have been shown to control light-regulated gene expression. They directly bind to the photoactivated phytochromes and are degraded in response to light signals. ALC, also termed AtbHLH73, or protein ALCATRAZ, or EN 98, is required for the dehiscence of fruit, especially for the separation of the valve cells from the replum. It promotes the differentiation of a strip of labile non-lignified cells sandwiched between layers of lignified cells. PIL1, also termed AtbHLH124, or protein phytochrome interacting factor 3-like 1, or EN 110, is involved in responses to transient and long-term shade. It is required for the light-mediated inhibition of hypocotyl elongation and necessary for rapid light-induced expression of the photomorphogenesis- and circadian-related gene APRR9. PIL1 seems to play a role in multiple PHYB responses, such as flowering transition and petiole elongation. SPATULA, also termed AtbHLH24, or EN 99, plays a role in floral organogenesis. It promotes the growth of carpel margins and of pollen tract tissues derived from them. UNE10, also termed AtbHLH16, or protein UNFERTILIZED EMBRYO SAC 10, or EN 99, is required during the fertilization of ovules by pollen.

                        10        20        30
                ....*....|....*....|....*....|....*.
gi 31317299  75 RLKELVPTLPQNRKVSKVEILQHVIDYIRDLQLELN 110
Cdd:cd11445  20 KMKALQELIPNCNKTDKASMLDEAIEYLKSLQLQVQ 55

basic helix-loop-helix-orange (bHLH-O) domain found in Drosophila melanogaster protein clockwork orange (Cwo) and similar proteins; Cwo is a bHLH-O transcriptional regulator involved in the regulation of Drosophila circadian rhythms. It functions as both an activator and a repressor of clock gene expression.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....
gi 31317299  69 MNGCYSRLKELVPT--LPQNR-KVSKVEILQHVIDYIRDLQLEL 109
Cdd:cd11440  17 MNNCLADLSRLIPPtyLKKGRgRIEKTEIIEMAIKHIKHLQQHA 60

basic helix-loop-helix (bHLH) domain found in transcription factor 15 (TCF-15) and similar proteins; 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
                ....*....|....*....|....*....|....*..
gi 31317299  69 MNGCYSRLKELVPTLPQNRKVSKVEILQHVIDYIRDL 105
Cdd:cd11470  23 VNTAFTALRTLIPTEPVDRKLSKIETLRLASSYIAHL 59