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        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1333158690 311 RAAEVHNLSERRRRDRINEKMKALQELIPRCNKVDKASMLDEAIEYLKSLQLQVQIMSMGCGMV 374
Cdd:cd11445     1 RAAEVHNLSERRRRDRINEKMKALQELIPNCNKTDKASMLDEAIEYLKSLQLQVQMMSMGNGMP 64

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        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1333158690 311 RAAEVHNLSERRRRDRINEKMKALQELIPRCNKVDKASMLDEAIEYLKSLQLQVQIMSMGCGMV 374
Cdd:cd11445     1 RAAEVHNLSERRRRDRINEKMKALQELIPNCNKTDKASMLDEAIEYLKSLQLQVQMMSMGNGMP 64

Helix-loop-helix DNA-binding domain;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1333158690 314 EVHNLSERRRRDRINEKMKALQELIPRCN---KVDKASMLDEAIEYLKSLQ 361
Cdd:pfam00010   3 EAHNERERRRRDRINDAFDELRELLPTLPpdkKLSKAEILRLAIEYIKHLQ 53

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        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1333158690 311 RAAEVHNLSERRRRDRINEKMKALQELIPRCNKVDKASMLDEAIEYLKSLQLQVQIMSMGCGMV 374
Cdd:cd11445     1 RAAEVHNLSERRRRDRINEKMKALQELIPNCNKTDKASMLDEAIEYLKSLQLQVQMMSMGNGMP 64

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana BIG PETAL (BPE) and similar proteins; The family includes several bHLH transcription factors from Arabidopsis thaliana, such as BPE, HBI1 and BEE proteins (BEE1-3). BPE, also termed AtbHLH31, or EN 88, is involved in the control of Arabidopsis petal size, by interfering with postmitotic cell expansion to limit final petal cell size. HBI1, also termed AtbHLH64, or homolog of bee2 interacting with IBH1, or EN 79, is an atypical bHLH transcription factor that acts as positive regulator of cell elongation downstream of multiple external and endogenous signals by direct binding to the promoters and activation of the two expansin genes EXPA1 and EXPA8, encoding cell wall loosening enzymes. BEEs, also termed protein Brassinosteroid enhanced expression, are positive regulators of brassinosteroid signaling.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1333158690 308 KRSRAAEVHNLSERRRRDRINEKMKALQELIPRCNKV-DKASMLDEAIEYLKSLQLQVQIMSM 369
Cdd:cd18919     8 RRGQATDSHSLAERVRREKISERMKLLQDLVPGCNKVtGKALMLDEIINYVQSLQRQVEFLSM 70

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana protein INDEHISCENT (IND) and similar proteins; The family includes several bHLH transcription factors from Arabidopsis thaliana, such as IND, HEC proteins (HEC1, HEC2 and HEC3) and UNE12. IND, also termed AtbHLH40, or EN 120, is a bHLH transcription regulator required for seed dispersal. It is involved in the differentiation of all three cell types required for fruit dehiscence. HEC1 (also termed AtbHLH88, or protein HECATE 1, or EN 118), HEC2 (also termed AtbHLH37, or protein HECATE 2, or EN 117) and HEC3 (also termed AtbHLH43, or protein HECATE 3, or EN 119) are required for the female reproductive tract development and fertility. Both IND and HEC proteins have been implicated in regulation of auxin signaling. They heterodimerize with SPATULA (SPT) bHLH transcription factor to regulate reproductive tract development in plant. UNE12, also termed AtbHLH59, or protein UNFERTILIZED EMBRYO SAC 12, or EN 93, is required for ovule fertilization.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1333158690 318 LSERRRRDRINEKMKALQELIPRCNKVDKASMLDEAIEYLKSLQLQVQIMSM 369
Cdd:cd11454     7 VAARHRRERISERIRILQRLVPGGTKMDTASMLDEAIHYVKFLQLQVKLLQS 58

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana protein transparent testa 8 (TT8) and similar proteins; The family includes several bHLH transcription factors from Arabidopsis thaliana, such as TT8, EGL1, and GL3. TT8, also termed AtbHLH42, or EN 32, is involved in the control of flavonoid pigmentation and plays a key role in regulating leucoanthocyanidin reductase (BANYULS) and dihydroflavonol-4-reductase (DFR). EGL1, also termed AtbHLH2, or EN 30, or AtMYC146, or protein enhancer of GLABRA 3, is involved in epidermal cell fate specification and regulates negatively stomata formation but promotes trichome formation. GL3, also termed AtbHLH1, or AtMYC6, or protein shapeshifter, or EN 31, is involved in epidermal cell fate specification. It regulates negatively stomata formation, but, in association with TTG1 and MYB0/GL1, promotes trichome formation, branching and endoreplication.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1333158690 316 HNLSERRRRDRINEKMKALQELIPRCNKVDKASMLDEAIEYLKSLQLQVQ 365
Cdd:cd11451     6 HAMAERRRREKLNERFITLRSMVPFVTKMDKVSILGDAIEYLKQLQRRVE 55

basic Helix-Loop-Helix (bHLH) domain found in Arabidopsis thaliana MYC1 and similar proteins; MYC1, also termed AtbHLH12, or EN 58, acts as a transcription activator, when associated with MYB75/PAP1 or MYB90/PAP2.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1333158690 316 HNLSERRRRDRINEKMKALQELIPRCNKVDKASMLDEAIEYLKSLQLQVQ 365
Cdd:cd18918     1 LFATERERREKLNEKFSDLRNLIPNPTKNDRASILSDAIKYINELQRTVE 50

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana protein aborted microspores (AMS) and similar proteins; The family includes several bHLH transcription factors from Arabidopsis thaliana, such as AMS, ICE1 and SCREAM2. AMS, also termed AtbHLH21, or EN 48, plays a crucial role in tapetum development and it is required for male fertility and pollen differentiation. ICE1, also termed inducer of CBF expression 1, or AtbHLH116, or EN 45, or SCREAM, acts as a transcriptional activator that regulates the cold-induced transcription of CBF/DREB1 genes. It binds specifically to the MYC recognition sites (5'-CANNTG-3') found in the CBF3/DREB1A promoter. SCREAM2, also termed AtbHLH33, or EN 44, mediates stomatal differentiation in the epidermis probably by controlling successive roles of SPCH, MUTE, and FAMA.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1333158690 317 NL-SERRRRDRINEKMKALQELIPRCNKVDKASMLDEAIEYLKSLQLQVQ 365
Cdd:cd11443     3 NLmAERRRRKKLNDRLYMLRSVVPKITKMDRASILGDAIDYVKELLQEIN 52

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana BES1-interacting Myc-like proteins (BIMs) and similar proteins; The family includes Arabidopsis thaliana BIM1 and its homologs (BIM2 and BIM3), which are bHLH transcription factors that interact with BES1 to regulate transcription of Brassinosteroid (BR)-induced gene. BR regulates many growth and developmental processes such as cell elongation, vascular development, senescence stress responses, and photomorphogenesis. BIM1 heterodimerize with BES1 and bind to E-box sequences present in many BR-induced promoters to regulated BR-induced genes.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1333158690 306 STKRSRaaevHNLSERRRRDRINEKMKALQELIPRCN-KVDKASMLDEAIEYLKSLQLQVQI 366
Cdd:cd11453     1 STPRSK----HSATEQRRRSKINERLQALRDLIPHSDqKRDKASFLLEVIEYIQALQEKVAK 58

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in USF/MITF family; The USF (upstream stimulatory factor)/MITF (microphthalmia-associated transcription factor) family includes two bHLHzip transcription factor subfamilies. USFs are ubiquitously expressed and key regulators of a wide number of gene regulation networks, including the stress and immune responses, cell cycle and proliferation, lipid and glucid metabolism. USFs recruit chromatin remodeling enzymes and interact with co-activators and the members of the transcription pre-initiation complex. USFs interact with high affinity to E-box regulatory elements. The MITF (also known as microphthalmia-TFE, or MiT) subfamily comprises four genes in mammals (MITF, TFE3, TFEB, and TFEC); each gene has different functions. MITF is involved in neural crest melanocytes development as well as the pigmented retinal epithelium. TFEB is required for vascularization of the mouse placenta. TFE3 is involved in B cell function. TFEC regulates gene expression in macrophages. The MITF subfamily proteins can form homodimers or heterodimers with each other but not with other bHLH or bHLHzip proteins.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1333158690 316 HNLSERRRRDRINEKMKALQELIPRCNKVD------KASMLDEAIEYLKSLQLQVQ 365
Cdd:cd11387     2 HNAVERRRRDNINEKIQELGSLVPPSRLETkdlkpnKGSILSKAVEYIRELQNQNQ 57

basic helix-loop-helix (bHLH) domain found in the spermatogenesis- and oogenesis-specific basic helix-loop-helix-containing protein (SOHLH) family and similar proteins; The SOHLH family includes two bHLH transcription factors, SOHLH1 and SOHLH2. They are specifically in spermatogonia and oocytes and essential for early spermatogonial and oocyte differentiation. The family also includes transcription factor-like 5 protein (TCFL5) and similar proteins. TCFL5, also termed Cha transcription factor, or HPV-16 E2-binding protein 1 (E2BP-1), is a bHLH transcription factor that plays a crucial role in spermatogenesis. It regulates cell proliferation or differentiation of cells through binding to a specific DNA sequence like other bHLH molecules.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1333158690 314 EVHNLSERRRRDRINEKMKALQELIPRCN-KVDKASMLDEAIEYLKSLQ 361
Cdd:cd19683     4 ERHNAKERQRRERIKIACDQLRKLVPGCSrKTDKATVFEFTVAYIKFLR 52

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana ILI1-BINDING BHLH 1 (IBH1) and similar proteins; The family includes several bHLH transcription factors from Arabidopsis thaliana, such as IBH1, UPBEAT1, PAR1 and PAR2. IBH1, also termed bHLH zeta, or AtbHLH158, is an atypical and probable non DNA-binding bHLH transcription factor that acts as transcriptional repressor that negatively regulates cell and organ elongation in response to gibberellin (GA) and brassinosteroid (BR) signaling. IBH1 forms heterodimer with BHLH49, thus inhibiting DNA binding of BHLH49, which is a transcriptional activator that regulates the expression of a subset of genes involved in cell expansion by binding to the G-box motif. UPBEAT1, also termed AtbHLH151, or EN 146, is a bHLH transcription factor that modulates the balance between cellular proliferation and differentiation in root growth. It does not act through cytokinin and auxin signaling, but by repressing peroxidase expression in the elongation zone. PAR1 (also termed AtbHLH165, or protein helix-loop-helix 1, or protein phytochrome rapidly regulated 1) and PAR2 (also termed AtbHLH166, or protein helix-loop-helix 2, or protein phytochrome rapidly regulated 2) are two atypical bHLH transcription factors that act as negative regulators of a variety of shade avoidance syndrome (SAS) responses, including seedling elongation and photosynthetic pigment accumulation. They act as direct transcriptional repressor of two auxin-responsive genes, SAUR15 and SAUR68. They may function in integrating shade and hormone transcriptional networks in response to light and auxin changes.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1333158690 319 SERRRRDRINEKMKALQELIPRCN-KVDKASMLDEAIEYLKSLQLQVQIMSM 369
Cdd:cd11444     4 RRRRGEEAIERRLRALRRLVPGGReSMEVEELLQETADYIMFLEMQVKVMKS 55

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana Fe-deficiency induced transcription factor 1 (FIT) and similar proteins; The family includes bHLH transcription factors from Arabidopsis thaliana, such as FIT and DYT1. FIT, also termed FER-like iron deficiency-induced transcription factor, or FER-like regulator of iron uptake, or AtbHLH29, or EN 43, is a bHLH transcription factor that is required for the iron deficiency response in plant. It regulates FRO2 at the level of mRNA accumulation and IRT1 at the level of protein accumulation. DYT1, also termed AtbHLH22, or protein dysfunctional tapetum 1, or EN 49, is a bHLH transcription factor involved in the control of tapetum development. It is required for male fertility and pollen differentiation, especially during callose deposition.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1333158690 319 SERRRRDRINEKMKALQELIPRCNKVDKASMLDEAIEYLKSLQLQVQ 365
Cdd:cd11450    10 SERNRRQKLNQRLFALRSVVPNITKMDKASIIKDAISYIQELQYQEK 56

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in transcription factor EB (TFEB) and similar proteins; TFEB, also termed Class E basic helix-loop-helix protein 35 (bHLHe35), is a bHLHzip transcription factor that is required for vascularization of the mouse placenta. It specifically recognizes and binds E-box sequences (5'-CANNTG-3'). Its efficient DNA-binding requires dimerization with itself or with another MiT/TFE family member such as TFE3 or MITF.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1333158690 308 KRSRAAEVHNLSERRRRDRINEKMKALQELIPRCNKVD----KASMLDEAIEYLKSLQLQVQ 365
Cdd:cd18927     7 KERQKKDNHNLIERRRRFNINDRIKELGTLIPKTNDLDvrwnKGTILKASVDYIKRMQKDLQ 68

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana suppressor of acaulis 51 (SAC51) and similar proteins; SAC51, also termed AtbHLH142, or EN 128, is a bHLH transcription factor that is involved in stem elongation, probably by regulating a subset of genes involved in this process.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1333158690 319 SERRRRDRINEKMKALQELIPRCNKVDKASMLDEAIEYLKSLQLQVQ 365
Cdd:cd18917     4 NEKSRKEKIKKAVKLLRSIVPGGESMDTALVLDEAIDYLKSLKMELQ 50

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1333158690 313 AEVHNLSERRRRDRINEKMKALQELIP----RCNKVDKASMLDEAIEYLKSLQL 362
Cdd:cd11391     1 REKSREAAKKRRDKENAEISELASLLPlppaVGSKLDKLSVLRLAVAYLRLKKF 54

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        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1333158690 308 KRSRAAevHNLSERRRRDRINEKMKALQELIPRCN------------------KVDKASMLDEAIEYLKSLQ 361
Cdd:cd11395     1 PRKRLP--HNAIEKRYRSNLNTKIERLRDAIPSLRspegksddgglgglapttKLSKATILTKAIEYIRHLE 70

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain found in aryl hydrocarbon receptor nuclear translocator-like protein 1 (ARNTL) and similar proteins; 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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1333158690 312 AAEVHNLSERRRRDRINEKMKALQELIPRCN----KVDKASMLDEAIEYLKSLQ 361
Cdd:cd11438     7 AREAHSQIEKRRRDKMNSFIDELASLVPTCNamsrKLDKLTVLRMAVQHMKTLR 60

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain found in aryl hydrocarbon receptor nuclear translocator-like protein 2 (ARNTL2) and similar proteins; 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. ARNT-2 heterodimerize with other bHLH-PAS proteins such as aryl hydrocarbon receptor (AhR), hypoxia-inducible factor (HIF), and single-minded (SIM).

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1333158690 314 EVHNLSERRRRDRINEKMKALQELIPRCN----KVDKASMLDEAIEYLKSLQ 361
Cdd:cd11469     3 EAHSQTEKRRRDKMNNLIEELSAMIPQCNpmarKLDKLTVLRMAVQHLKSLK 54

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.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1333158690 316 HNLSERRRRDRINEKMKALQELIPRCN----KVDKASMLDEAIEYLKSL 360
Cdd:cd11437     5 HSEIEKRRRDKMNAYIQELSALVPACNamsrKLDKLTVLRMAVQHLKSL 53

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in transcription factor E3 (TFE3) and similar proteins; TFE3, also termed Class E basic helix-loop-helix protein 33 (bHLHe33), is a bHLHzip transcription factor that is involved in B cell function. It specifically recognizes and binds E-box sequences (5'-CANNTG-3'). Its efficient DNA-binding requires dimerization with itself or with another MiT/TFE family member such as TFEB or MITF.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1333158690 308 KRSRAAEVHNLSERRRRDRINEKMKALQELIPRCN----KVDKASMLDEAIEYLKSLQLQVQ 365
Cdd:cd18928     7 KERQKKDNHNLIERRRRFNINDRIKELGTLIPKSTdpemRWNKGTILKASVDYIRKLQKEQQ 68

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in basic helix-loop-helix domain-containing protein USF3 and similar proteins; USF3, also termed upstream transcription factor 3, is a bHLHzip protein that is involved in the negative regulation of epithelial-mesenchymal transition, the process by which epithelial cells lose their polarity and adhesion properties to become mesenchymal cells with enhanced migration and invasive properties.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1333158690 308 KRSRAAEVHNLSERRRRDRINEKMKALQELIPRCN--KVDKASMLDEAIEYLKSLQ 361
Cdd:cd18910     1 RREKKRESHNEVERRRKDKINAGINKIGELLPDRDakKQSKNMILEQAYKYIVELK 56

basic helix-loop-helix-orange (bHLH-O) domain found in hairy and enhancer of split (HES)-related repressor protein (HERP) family; HERP (also called Hey/Hesr/HRT/CHF/gridlock) proteins corresponds to a family of bHLH-O transcriptional repressors that are related to the Drosophila hairy and Enhancer-of-split proteins and act as downstream effectors of Notch signaling. 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 are involved in cardiovascular development and have roles in somitogenesis, myogenesis and gliogenesis.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1333158690 320 ERRRRDRINEKMKALQELIPRC------NKVDKASMLDEAIEYLKSLQ 361
Cdd:cd11407     9 EKRRRDRINNSLAELRRLVPTAfekqgsAKLEKAEILQMTVDHLKMLH 56

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        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1333158690 308 KRSRAAevHNLSERRRRDRINEKMKALQELIPRCN-----KVDKASMLDEAIEYLKSLQLQVQIM 367
Cdd:cd11405     1 EQRRLS--HISAEQKRRFNIKSGFDTLQSLIPSLGqnpnqKVSKAAMLQKAAEYIKSLKRERQQM 63

basic helix-loop-helix-orange (bHLH-O) domain found in hairy and enhancer of split-related protein HELT and similar proteins; HELT, also termed HES/HEY-like transcription factor, is a bHLH-O 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. HELT could homodimerize and heterodimerize with other bHLH-O protein such as HES-5 or HEY-2 and bound to E box to repress gene transcription.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1333158690 316 HNLSERRRRDRINEKMKALQELIP------RCNKVDKASMLDEAIEYLKSLQ 361
Cdd:cd11408     2 HKVIEKRRRDRINRCLNELGKTVPmalakqTSGKLEKAEILEMTVQYLRALH 53

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana protein IAA-leucine resistant 3 (ILR3) and similar proteins; ILR3, also termed AtbHLH105, or EN 133, is a bHLH transcription factor that plays a role in resistance to amide-linked indole-3-acetic acid (IAA) conjugates such as IAA-Leu and IAA-Phe. It may regulate gene expression in response to metal homeostasis changes.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1333158690 320 ERRRRDRINEKMKALQELI-P-RCNKVDKASMLDEAIEYLKSLQLQVQ 365
Cdd:cd11446     5 EKLRRDKLNERFMELSNVLePgRPPKTDKATILGDAIRMLKQLRGEVQ 52

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in L-Myc and similar proteins; L-Myc, also termed Class E basic helix-loop-helix protein 38 (bHLHe38), or protein L-Myc-1, or V-myc myelocytomatosis viral oncogene homolog, is a bHLHZip oncoprotein belonging to the Myc oncogene protein family. It binds DNA as a heterodimer with MAX. L-Myc is co-expressed with another Myc family member and has weaker transformation/transactivation activities. L-Myc knockout mouse did not exhibit any phenotypic abnormalities.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1333158690 307 TKRSRaaevHNLSERRRRDRINEKMKALQELIP---RCNKVDKASMLDEAIEYLKSLQLQVQIMS 368
Cdd:cd11457     6 AKRKN----HNFLERKRRNDLRSRFLALRDEVPglaSCSKTPKVVILSKATEYLRGLVSAERRMA 66

basic helix-loop-helix-orange (bHLH-O) domain found in differentially expressed in chondrocytes protein (DEC) family; The DEC family includes two bHLH-O transcriptional repressors, DEC1 and DEC2, which 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. They mediate the circadian rhythm by negatively regulating the activity of the clock genes and clock-controlled genes. They are induced by CLOCK:BMAL1 heterodimer via the CACGTG E-box in the promoter.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1333158690 316 HNLSERRRRDRINEKMKALQELIPRCNK------VDKASMLDEAIEYLKSL-----QLQVQIMSMGCG 372
Cdd:cd11409     8 HRLIEKKRRDRINECIAQLKDLLPEHLKlttlghLEKAVVLELTLKHLKALtalteQQQQKIIALQNG 75

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in Saccharomyces cerevisiae transcription factor HMS1 and similar proteins; HMS1, also termed high-copy MEP suppressor protein 1, is a putative bHLHzip transcription factor involved in exit from mitosis and pseudohyphal differentiation.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1333158690 316 HNLSERRRRDRINEKMKALQELIPRC-----------------------NKVDKASMLDEAIEYLKSLQ-------LQVQ 365
Cdd:cd11399     7 HNMIEKRYRSNINDRIAELRDSVPALreayksargededeedlggltpaTKLNKATILSKATEYIRHLEkknkrlsRENA 86

                  ....
gi 1333158690 366 IMSM 369
Cdd:cd11399    87 SLRE 90

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain found in Drosophila melanogaster protein cycle and similar proteins; 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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1333158690 316 HNLSERRRRDRINEKMKALQELIPRCN----KVDKASMLDEAIEYLKSLQ 361
Cdd:cd19726     5 HSEIEKRRRDKMNTYITELSSMIPMCNamsrKLDKLTVLRMAVQHMKTLR 54

basic helix-loop-helix-orange (bHLH-O) domain found in Drosophila melanogaster Enhancer of split proteins, E(spl)m5, E(spl)m8 and similar proteins; The family includes two bHLH-O transcriptional repressors, E(spl)m5 and E(spl)m8, which participate in the control of cell fate choice by uncommitted neuroectodermal cells in the embryo. They bind DNA on N-box motifs, 5'-CACNAG-3'.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1333158690 318 LSERRRRDRINEKMKALQELIPR------CNKVDKASMLDEAIEYLKSLQ 361
Cdd:cd18916     6 MLERQRRARINKCLSELKTLVAEcsgddgCLRMDKAEMLETAVAFMRQQQ 55

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in upstream stimulatory factor 1 (USF1) and similar proteins; USF1, also termed Class B basic helix-loop-helix protein 11 (bHLHb11), or major late transcription factor 1, is a bHLHzip transcription factor that binds to a symmetrical DNA sequence (E-boxes) (5'-CACGTG-3') that is found in a variety of viral and cellular promoters. It is ubiquitously expressed and involved in the transcription activation of various functional genes implicated in lipid and glucose metabolism, stress response, immune response, cell cycle control and tumour suppression. USF-1 recruits chromatin remodeling enzymes and interact with co-activators and the members of the transcription pre-initiation complex. Genetic polymorphisms of USF1 are associated with some metabolic and cardiovascular diseases, like diabetes, atherosclerosis, coronary artery calcifications and familial combined hyperlipidaemia (FCHL).

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1333158690 316 HNLSERRRRDRINEKMKALQELIPRC------NKVDKASMLDEAIEYLKSLQ 361
Cdd:cd18924     9 HNEVERRRRDKINNWIVQLSKIIPDCsmestkSGQSKGGILSKACDYIQELR 60

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        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1333158690 316 HNLSERRRRDRINEKMKALQELIPRC------NKVDKASMLDEAIEYLKSLQLQ 363
Cdd:cd11440     6 HRIIEKRRRDRMNNCLADLSRLIPPTylkkgrGRIEKTEIIEMAIKHIKHLQQH 59

basic helix-loop-helix-orange (bHLH-O) domain found in transcription factor HES-3 and similar proteins; HES-3, also termed Class B basic helix-loop-helix protein 43 (bHLHb43), or hairy and enhancer of split 3, is a bHLH-O transcription factor expressed in neural stem and progenitor cells that is involved in tissue regeneration. It regulates gene expression, cell growth, and insulin release. HES-3 is one mammalian counterpart of the Hairy and Enhancer of split proteins that play a critical role in many physiological processes including cellular differentiation, cell cycle arrest, apoptosis and self-renewal ability.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1333158690 320 ERRRRDRINEKMKALQELIP-------RCNKVDKASMLDEAIEYLKSLQLQVQ 365
Cdd:cd18933     2 EKKRRARINVSLEQLKSLLEkhysnniRKRKLEKADILELTVKYLRSLQNSIQ 54

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.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1333158690 316 HNLSERRRRDRINEKMKALQELI-PRCNKVDKASMLDEAIEYLKSLQ 361
Cdd:cd11394    10 HNAIEKRYRSSINDRIIELKDLVvGPDAKMNKSAVLRKAIDYIRYLQ 56

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 1333158690 317 NLSERRRRDRINEKMKALQELIP---RCNKVDKASMLDEAIEYLKSLQ 361
Cdd:cd11418     6 NERERRRVQAVNDAFDRLRQHVPylkRRKKLSKVKTLRRAIEYIRHLQ 53

basic helix-loop-helix (bHLH) domain found in Saccharomyces cerevisiae phosphate system positive regulatory protein PHO4 and similar proteins; PHO4 is a transcriptional activator that regulates the expression of repressible phosphatase under phosphate starvation conditions in Saccharomyces cerevisiae. The PHO4 protein has four functional domains with the bHLH domain at its carboxyl-terminal region. It regulates transcription by binding to promoter of the genes as a homodimer.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1333158690 316 HNLSERRRRDRINEKMKALQELIPRCNKVD------------------------KASMLDEAIEYLKSLQLQV 364
Cdd:cd11392     6 HKVAERGRRDRLNAALKELASLMPAEFVEGkmgadgsasdsndkekaaasaagsKAATVEMAIDYIKHLQKEV 78

basic helix-loop-helix-orange (bHLH-O) domain found in Drosophila melanogaster enhancer of split mbeta protein (ESMB) and similar proteins; ESMB, also termed E(spl)mbeta, or HLH-mbeta, or split locus enhancer protein mA, is a bHLH-O transcriptional repressor of genes that require a bHLH protein for their transcription. It is involved in the neural-epidermal lineage decision during early neurogenesis. The family also includes Enhancer of split m7 protein (also known as E(spl)m7), which acts as a transcriptional repressor that participates in the control of cell fate choice by uncommitted neuroectodermal cells in the embryo.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1333158690 318 LSERRRRDRINEKMKALQELIPRC--------NKVDKASMLDEAIEYLKSLQLQ 363
Cdd:cd19741    14 LLERKRRARINKCLDELKDLMVEAlateaenvSKLEKADILELTVRHLKKLRRQ 67

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 1333158690 315 VHNLSERRRRDRINEKMKALQELIP---RCNKVDKASMLDEAIEYLKSLQ 361
Cdd:cd11400     4 LHNVLERQRRNDLKNSFEKLRDLVPelaDNEKASKVVILKKATEYIKQLQ 53

basic helix-loop-helix-orange (bHLH-O) domain found in Drosophila melanogaster protein hairy, protein deadpan and similar proteins; Protein hairy is a bHLH transcriptional repressor of genes that require a bHLH-O protein for their transcription. It acts as a pair-rule protein that regulates embryonic segmentation and adult bristle patterning. Protein deadpan is closely related to the product of the segmentation gene hairy. It is a direct target of Notch signaling and regulates neuroblast self-renewal in Drosophila.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1333158690 320 ERRRRDRINEKMKALQELI--------PRCNKVDKASMLDEAIEYLKSLQLQ 363
Cdd:cd18913    11 EKRRRARINASLNELKSLLldalkkdgTRHSKLEKADILEMTVKHLRQVQRQ 62

basic helix-loop-helix-orange (bHLH-O) domain found in hairy/enhancer-of-split related with YRPW motif protein 2 (HEY2) and similar proteins; HEY2, also termed cardiovascular helix-loop-helix factor 1 (CHF-1), or Class B basic helix-loop-helix protein 32 (bHLHb32), or HES-related repressor protein 2, or hairy and enhancer of split-related protein 2 (HESR-2), or hairy-related transcription factor 2 (HRT-2), or protein gridlock homolog, is a bHLH-O transcriptional repressor expressed preferentially in the developing and adult cardiovascular system. As a downstream effector of Notch signaling, HEY2 may be required for cardiovascular development. It also plays an important role in neurologic development, as well as in the progression of human cancers.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1333158690 320 ERRRRDRINEKMKALQELIPRC------NKVDKASMLDEAIEYLKSLQ 361
Cdd:cd18920    18 EKRRRDRINNSLSELRRLVPTAfekqgsAKLEKAEILQMTVDHLKMLQ 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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1333158690 316 HNLSERRRRDRINEKMKALQELIPRCNKVDKAS---MLDEAIEYLKSLQLQVQ 365
Cdd:cd11456     9 HNILERQRRNDLRSSFLTLRDHVPELVKNEKAAkvvILKKATEYVHSLQAEEQ 61

basic helix-loop-helix (bHLH) domain found in transcription factor-like 5 protein (TCFL5) and similar proteins; TCFL5, also termed Cha transcription factor, or HPV-16 E2-binding protein 1 (E2BP-1), is a bHLH transcription factor that plays a crucial role in spermatogenesis. It regulates cell proliferation or differentiation of cells through binding to a specific DNA sequence like other bHLH molecules.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1333158690 314 EVHNLSERRRRDRINEKMKALQELIPRCN-KVDKASMLDEAIEYLKSLQ 361
Cdd:cd18909     4 ERHNRMERDRRRRIRICCDELNLLVPFCNaETDKATTLQWTTAFLKYIQ 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 1333158690 316 HNLSERRRRDRINEKMKALQELIP--RCNKVDKASMLDEAIEYLKSLQLQVQIM 367
Cdd:cd19690     4 HKLAERKRRKEMKELFEDLRDALPqeRGTKASKWEILTKAISYIQQLKRHIREL 57