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        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 665389470 381 GTREVHNKLEKERRAQLKECYDLLKKVLPMGDedRKKTSNLTILDTAHKYVNSLSHEVCEQEAKIEKLAKQKIELQKRL 459
Cdd:cd11402    1 GTREVHNKLEKNRRAHLKECFETLKRQIPNLD--DKKTSNLNILRSALRYIQILKRKEKEYEHEMERLAREKIALQQRL 77

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        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 665389470 381 GTREVHNKLEKERRAQLKECYDLLKKVLPMGDedRKKTSNLTILDTAHKYVNSLSHEVCEQEAKIEKLAKQKIELQKRL 459
Cdd:cd11402    1 GTREVHNKLEKNRRAHLKECFETLKRQIPNLD--DKKTSNLNILRSALRYIQILKRKEKEYEHEMERLAREKIALQQRL 77

helix loop helix domain;

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|..
gi 665389470   387 NKLEKERRAQLKECYDLLKKVLPMGDEDrKKTSNLTILDTAHKYVNSLSHEV 438
Cdd:smart00353   1 NARERRRRRKINEAFDELRSLLPTLPKN-KKLSKAEILRLAIEYIKSLQEEL 51

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        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 665389470 381 GTREVHNKLEKERRAQLKECYDLLKKVLPMGDedRKKTSNLTILDTAHKYVNSLSHEVCEQEAKIEKLAKQKIELQKRL 459
Cdd:cd11402    1 GTREVHNKLEKNRRAHLKECFETLKRQIPNLD--DKKTSNLNILRSALRYIQILKRKEKEYEHEMERLAREKIALQQRL 77

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in the Mad family; Members of the Mad family (Mad1, Mxi, Mad3, and Mad4) bear the bHLHzip domain (also known as basic-helix-loop-helix-leucine-zipper or bHLH-LZ domain), which mediates heterodimerization to Max and the sequence-specific DNA binding ability to E-box DNA. Mad family proteins can repress transcription at the E-box through their interaction with co-repressors. Mad family proteins antagonize Myc function in transactivation and transformation and they are growth/tumor suppressors. The developmental phenotypes of the individual Mad family member knockout mice are relatively mild- all these mice have been shown to be viable and normal.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 665389470 383 REVHNKLEKERRAQLKECYDLLKKVLPMGDEDRKKTSnLTILDTAHKYVNSLSHEVCEQEAKIEKLAKQKIELQKRL 459
Cdd:cd11401    1 RSTHNELEKNRRAHLRLCLERLKELVPLGPDATRHTT-LSLLTKAKAYIKNLEDKEKRQRQQKEQLRREQRELKRRL 76

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in Max-interacting protein 1 (MXI1) and similar proteins; MXI1, also termed Max interactor 1, or Class C basic helix-loop-helix protein 11 (bHLHc11), is a bHLHZip transcriptional repressor that binds with MAX to form a sequence-specific DNA-binding protein complex which recognizes the core sequence 5'-CAC[GA]TG-3'. It thus antagonizes MYC transcriptional activity by competing for MAX. It plays an important role in the regulation of cell proliferation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389470 383 REVHNKLEKERRAQLKECYDLLKKVLPMGDEDRKKTSnLTILDTAHKYVNSLSHEVCEQEAKIEKLAKQKIELQKRLKQL 462
Cdd:cd18930    2 RSTHNELEKNRRAHLRLCLERLKVLIPLGPDCTRHTT-LGLLNKAKAHIKKLEEADRKSQHQLENLEREQRFLKRRLEQL 80

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in Max-associated protein 3 (Mad3) and similar proteins; Mad3, also termed Max dimerization protein 3, or Max dimerizer 3 (MXD3), or Class C basic helix-loop-helix protein 13 (bHLHc13), or Max-interacting transcriptional repressor MAD3, or Myx, is a bHLHZip Max-interacting transcriptional repressor that plays an important role in cellular proliferation. It suppresses c-myc dependent transformation and is expressed during neural and epidermal differentiation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389470 383 REVHNKLEKERRAQLKECYDLLKKVLPMGDEDRKKTSnLTILDTAHKYVNSLshevCEQEAKI----EKLAKQKIELQKR 458
Cdd:cd18932    7 RSVHNELEKHRRAQLRRCLEQLKQQVPLGADCSRYTT-LSLLRRARLHIQKL----EEQEQRAqqlkERLRWEQQKLRRR 81

                 ....
gi 665389470 459 LKQL 462
Cdd:cd18932   82 LESL 85

helix loop helix domain;

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|..
gi 665389470   387 NKLEKERRAQLKECYDLLKKVLPMGDEDrKKTSNLTILDTAHKYVNSLSHEV 438
Cdd:smart00353   1 NARERRRRRKINEAFDELRSLLPTLPKN-KKLSKAEILRLAIEYIKSLQEEL 51

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in c-Myc and similar proteins; c-Myc, also termed Myc proto-oncogene protein, or Class E basic helix-loop-helix protein 39 (bHLHe39), or transcription factor p64, a bHLHZip proto-oncogene protein that functions as a transcription factor, which binds DNA in a non-specific manner, yet also specifically recognizes the core sequence 5'-CAC[GA]TG-3'. It activates the transcription of growth-related genes.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389470 383 REVHNKLEKERRAQLKECYDLLKKVLPMGdEDRKKTSNLTILDTAHKYVNSLSHEVCEQEAKIEKLAKQKIELQKRLKQL 462
Cdd:cd11458    6 RRTHNVLERQRRNELKLSFFALRDQIPEV-ANNEKAPKVVILKKATEYILSMQADEQRLISEKEQLRRRREQLKHRLEQL 84

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        40
                 ....*....|....*....|....*....|....*....|....*
gi 665389470 390 EKERRAQLKECYDLLKKVLPMGdEDRKKTSNLTILDTAHKYVNSL 434
Cdd:cd00083    1 ERRRRDKINDAFEELKRLLPEL-PDSKKLSKASILQKAVEYIREL 44

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        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389470 383 REVHNKLEKERRAQLKECYDLLKKVLPMGDEDrKKTSNLTILDTAHKYVNSLSHEVCEQEAKIEKLAKQKIELQKRLKQL 462
Cdd:cd11456    6 RRNHNILERQRRNDLRSSFLTLRDHVPELVKN-EKAAKVVILKKATEYVHSLQAEEQKLLLEKEKLQARQQQLLKKIEQA 84

                 ...
gi 665389470 463 SLR 465
Cdd:cd11456   85 RTC 87

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 665389470 383 REVHNKLEKERRAQLKECYDLLKKVLPMGDEdrkKTSNLTILDTAHKYV 431
Cdd:cd19683    3 RERHNAKERQRRERIKIACDQLRKLVPGCSR---KTDKATVFEFTVAYI 48

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        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 665389470 383 REVHNKLEKERRAQLKECYDLLKKVLPmgDEDRKKTSNLTILDTAHKYVNSLSHEVCEQEAKIEKL 448
Cdd:cd19690    1 RVSHKLAERKRRKEMKELFEDLRDALP--QERGTKASKWEILTKAISYIQQLKRHIRELRSEVNDL 64

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana genes coding transcription factors and similar proteins; bHLH proteins are the second largest class of plant transcription factors that regulate transcription of genes that are involve in many essential physiological and developmental process. bHLH proteins are transcriptional regulators that are found in organisms from yeast to humans. The Arabidopsis bHLH proteins that have been characterized so far have roles in regulation of fruit dehiscence, cell development (carpel, anther and epidermal), phytochrome signaling, flavonoid biosynthesis, hormone signaling and stress responses.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 665389470 386 HNKLEKERRAQLKECYDLLKKVLPMGdedrKKTSNLTILDTAHKYVNSLSHEV 438
Cdd:cd11393    1 HSIAERKRREKINERIRALRSLVPNG----GKTDKASILDEAIEYIKFLQEQV 49

basic helix-loop-helix (bHLH) domain found in Saccharomyces cerevisiae protein INO2 and similar proteins; INO2 is a positive regulatory factor required for depression of the co-regulated phospholipid biosynthetic enzymes in Saccharomyces cerevisiae. It is also involved in the expression of ITR1.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 665389470 383 REVHNKLEKERRAQLKECYDLLKKVLPM-GDEDRKKTSNLTILdtahkyvnslsHEVCEQeakIEKLAKQKIELQKRLK 460
Cdd:cd11388    4 KWKHVEAEKKRRNQIKKGFEDLINLINYpRNNNEKRISKSELL-----------NKAVDD---IRGLLKANEQLQEEIN 68

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        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 665389470 386 HNKLEKERRAQLKECYDLLKKVLPmgdeDRKKTSNLTILDTAHKYVNSLSHEVCEQEAKIEK 447
Cdd:cd18918    1 LFATERERREKLNEKFSDLRNLIP----NPTKNDRASILSDAIKYINELQRTVEELKSLVEK 58

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
                 ....*....|....*....|....*....|....*....
gi 665389470 383 REVHNKLEKERRAQLKECYDLLKKVLPMGDEDRKKTSNL 421
Cdd:cd18909    3 RERHNRMERDRRRRIRICCDELNLLVPFCNAETDKATTL 41

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

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 665389470 390 EKERRAQLKECYDLLKKVLPM--GDEDRKKTSNLTILDTAHKYVNSLSHEV 438
Cdd:cd19685    2 EKRRRQRINDKLNQLKELLPPnlSKQSRSKLSKAEILEMAITELRRLQQEV 52