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        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1350186531 137 DYIHVRARRGQATDSHSLAERARREKISERMKLLQDLVPGCNKVIGKALVLDEIINYIQSLQHQVEFLSMKLEAVNSRMN 216
Cdd:cd18919     1 DYIHVRARRGQATDSHSLAERVRREKISERMKLLQDLVPGCNKVTGKALMLDEIINYVQSLQRQVEFLSMKLAAVNPRLD 80

                  ....
gi 1350186531 217 LNPT 220
Cdd:cd18919    81 FNSE 84

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        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1350186531 137 DYIHVRARRGQATDSHSLAERARREKISERMKLLQDLVPGCNKVIGKALVLDEIINYIQSLQHQVEFLSMKLEAVNSRMN 216
Cdd:cd18919     1 DYIHVRARRGQATDSHSLAERVRREKISERMKLLQDLVPGCNKVTGKALMLDEIINYVQSLQRQVEFLSMKLAAVNPRLD 80

                  ....
gi 1350186531 217 LNPT 220
Cdd:cd18919    81 FNSE 84

Helix-loop-helix DNA-binding domain;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1350186531 151 SHSLAERARREKISERMKLLQDLVP--GCNKVIGKALVLDEIINYIQSLQ 198
Cdd:pfam00010   4 AHNERERRRRDRINDAFDELRELLPtlPPDKKLSKAEILRLAIEYIKHLQ 53

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        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1350186531 137 DYIHVRARRGQATDSHSLAERARREKISERMKLLQDLVPGCNKVIGKALVLDEIINYIQSLQHQVEFLSMKLEAVNSRMN 216
Cdd:cd18919     1 DYIHVRARRGQATDSHSLAERVRREKISERMKLLQDLVPGCNKVTGKALMLDEIINYVQSLQRQVEFLSMKLAAVNPRLD 80

                  ....
gi 1350186531 217 LNPT 220
Cdd:cd18919    81 FNSE 84

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
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1350186531 148 ATDSHSLAERARREKISERMKLLQDLVPGCNKViGKALVLDEIINYIQSLQHQVEFLSM 206
Cdd:cd11445     2 AAEVHNLSERRRRDRINEKMKALQELIPNCNKT-DKASMLDEAIEYLKSLQLQVQMMSM 59

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 1350186531 151 SHSLAERARREKISERMKLLQDLVPGCNKVIGKALVLDEIINYIQSLQHQVEFLSMKLEAVNS 213
Cdd:cd11453     6 KHSATEQRRRSKINERLQALRDLIPHSDQKRDKASFLLEVIEYIQALQEKVAKLEEQVQGWGG 68

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 1350186531 155 AERARREKISERMKLLQDLVPGCNKVIGKALVLDEIINYIQSLQHQVEFLSMKL 208
Cdd:cd11444     4 RRRRGEEAIERRLRALRRLVPGGRESMEVEELLQETADYIMFLEMQVKVMKSLV 57

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 1350186531 149 TDSHSLAERARREKISERMKLLQDLVPGCNKvIGKALVLDEIINYIQSLQHQVEFL 204
Cdd:cd11451     3 DGSHAMAERRRREKLNERFITLRSMVPFVTK-MDKVSILGDAIEYLKQLQRRVEEL 57

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in Saccharomyces cerevisiae centromere-binding protein 1 (CBP-1) and similar proteins; CBP-1, also termed centromere promoter factor 1 (CPF1), or centromere-binding factor 1 (CBF1), is a bHLHzip protein that is required for chromosome stability and methionine prototrophy. It binds as a homodimer to the centromere DNA elements I (CDEI, GTCACATG) region of the centromere that is required for optimal centromere function.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1350186531 141 VRARRgqatDSHSLAERARREKISERMKLLQDLVPGCNKVIGKALVLDEIINYIQSLQHQVE 202
Cdd:cd11398     4 HRQRR----DNHKEVERRRRENINEGINELAALVPGNAREKNKGAILARAVEYIQELQETEA 61

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 1350186531 156 ERARREKISERMKLLQDLVPGC--NKVIGKALVLDEIINYIQSLQ 198
Cdd:cd00083     1 ERRRRDKINDAFEELKRLLPELpdSKKLSKASILQKAVEYIRELQ 45

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 1350186531 151 SHSLAERARREKISERMKLLQDLVPGCNKVIG-----KALVLDEIINYIQSLQHQVE 202
Cdd:cd11387     1 SHNAVERRRRDNINEKIQELGSLVPPSRLETKdlkpnKGSILSKAVEYIRELQNQNQ 57

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        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1350186531 144 RRGQAtdsHSLAERARREKISERMKLLQDLVPGCNKV-IGKALVLDEIINYIQSLQHQVEFLSMKLEAVNSRM 215
Cdd:cd11404     1 QRRLN---HVRSEKKRRELIKKGYDELCALVPGLDPQkRTKADILQKAADWIQELKEENEKLEEQLDELKEAA 70

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana protein ABA-INDUCIBLE bHLH-TYPE (AIB) and similar proteins; The family includes several bHLH transcription factors from Arabidopsis thaliana, such as AIB and MYC proteins (MYC2, MYC3 and MYC4). AIB, also termed AtbHLH17, or EN 35, is a transcription activator that regulates positively abscisic acid (ABA) response. MYC2, also termed protein jasmonate insensitive 1, or R-homologous Arabidopsis protein 1 (RAP-1), or AtbHLH6, or EN 38, or Z-box binding factor 1 protein, is a transcriptional activator involved in abscisic acid (ABA), jasmonic acid (JA), and light signaling pathways. MYC3, also termed protein altered tryptophan regulation 2, or AtbHLH5, or transcription factor ATR2, or EN 36, is a transcription factor involved in tryptophan, jasmonic acid (JA) and other stress-responsive gene regulation. MYC4, also termed AtbHLH4, or EN 37, is a transcription factor involved in jasmonic acid (JA) gene regulation. MYC2, together with MYC3 and MYC4, controls additively subsets of JA-dependent responses.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1350186531 151 SHSLAERARREKISERMKLLQDLVPGCNKvIGKALVLDEIINYIQSLQHQVEFLSMKLEAVNSRMN 216
Cdd:cd11449     8 NHVEAERQRREKLNQRFYALRAVVPNVSK-MDKASLLGDAISYINELKSKVQDMETEKKEMKRQES 72

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in upstream stimulatory factors, USF1, USF2 and similar proteins; Upstream stimulatory factor 1 and 2 (USF-1 and USF-2) are members of bHLHzip transcription factor family. 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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1350186531 151 SHSLAERARREKISERMKLLQDLVPGCNKVIG-----KALVLDEIINYIQSLQHQVE 202
Cdd:cd11396     1 THNEVERRRRDKINNWIVKLAKIVPDCEKDNSkqgqsKGGILSKACDYIQELRSQNE 57

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 1350186531 156 ERARREKISERMKLLQDLVPGcNKVIGKALVLDEIINYIQSLQHQVE 202
Cdd:cd18917     5 EKSRKEKIKKAVKLLRSIVPG-GESMDTALVLDEAIDYLKSLKMELQ 50

basic helix-loop-helix (bHLH) domain found in the spermatogenesis- and oogenesis-specific basic helix-loop-helix-containing protein (SOHLH) family; 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.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1350186531 151 SHSLAERARREKISERMKLLQDLVPGCNKV-IGKALVLDEIINYIQSLQ 198
Cdd:cd18908     5 SHSLKERLRRERIKSSCDQLRDLLPYIKGRkLDMASVLEMTVKYIRYIQ 53

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in sterol regulatory element-binding protein 1 (SREBP1) and similar proteins; SREBP1, also termed Class D basic helix-loop-helix protein 1 (bHLHd1), or sterol regulatory element-binding transcription factor 1 (SREBF1), is a member of a family of bHLHzip transcription factors that recognize sterol regulatory element 1 (SRE-1). It acts as a transcriptional activator required for lipid homeostasis. It may control transcription of the low-density lipoprotein receptor gene as well as the fatty acid. SREBP1 has dual sequence specificity binding to both an E-box motif (5'-ATCACGTGA-3') and to SRE-1 (5'-ATCACCCCAC-3').

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1350186531 145 RGQATDSHSLAERARREKISERMKLLQDLVPGCNKVIGKALVLDEIINYIQSLQHQVEFLsmKLEAVNSRMNL 217
Cdd:cd18921     3 KGEKRTAHNAIEKRYRSSINDKIIELKDLVVGTEAKLNKSAVLRKAIDYIRFLQQSNQKL--KQENMALKMAV 73

mucin-associated surface protein (MASP); Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1350186531  38 GGFGESSANRDG-SMEESTVTEQSGGGGGR-----KRRDVSSEdeSSKLVSTSSANDLNnTNGKRTKLVGSK-YENGGPK 110
Cdd:PTZ00459   94 GAEDEEEEKVRGqSGQEGTVALGSGSTEKKligseKQTELSIS--SAESISPSGSRELN-VNLTQTEVEGKKeTDKNTPA 170

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 1350186531 111 AEAEASSVGGDK--PAE-KEMKPSEPPKQDYIHVRARRGQATDS 151
Cdd:PTZ00459  171 VENPLTTGNGENtlPAGiVEGNPSPPPPQDGIHSREQDGEGTTS 214

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in sterol regulatory element-binding protein 2 (SREBP2) and similar proteins; SREBP2, also termed Class D basic helix-loop-helix protein 2 (bHLHd2), or sterol regulatory element-binding transcription factor 2 (SREBF2), is a member of a family of bHLHzip transcription factors that recognize sterol regulatory element 1 (SRE-1). It acts as a transcription activator of cholesterol biosynthesis.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1350186531 144 RRGQATDSHSLAERARREKISERMKLLQDLVPGCNKVIGKALVLDEIINYIQSLQ---HQVEFLSMKLEAVNSR 214
Cdd:cd18922     2 KEGERRTTHNIIEKRYRSSINDKIIELKDLVMGTDAKMHKSGVLRKAIDYIKYLQqvnHKLRQENMALKLANQK 75

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
                  ....*....|....*....|....*....|....*....|....*..
gi 1350186531 159 RREKISERMKLLQDLVPGC--NKVIGKALVLDEIINYIQSLQHQVEF 203
Cdd:cd19695     4 ERREMALYLAKLRNLVPTLpkNRKVSKLELLQHVIDYIADLEEQLED 50

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in MAX gene-associated protein (MGA) family; The MGA family includes MGA, Schizosaccharomyces pombe ESC1 (spESC1) and similar proteins. MGA, also termed MAX dimerization protein 5 (MAD5), is a dual specificity T-box/ bHLHzip transcription factor that regulates the expression of both Max-network and T-box family target genes. It contains a Myc-like bHLHZip motif and requires heterodimerization with Max for binding to the preferred Myc-Max-binding site CACGTG. In addition to the bHLHZip domain, MGA harbors a second DNA-binding domain, the T-box or T-domain. It thus binds the preferred Brachyury-binding sequence and represses transcription of reporter genes containing promoter-proximal Brachyury-binding sites. 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 1350186531 152 HSLAERARREKISERMKLLQDLVPGCNKV-IGKALVLDEIINYIQSLQHQVEFL 204
Cdd:cd19682     4 HKKRERERRSELRELFDKLKQLLGLDSDEkASKLAVLTEAIEEIQQLKREEDEL 57

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 1350186531 152 HSLAERARREKISERMKLLQDLVPGCNKV-----IGKALVLDEIINYIQSLQHQVEFLSMKLEAVNS 213
Cdd:cd11409     8 HRLIEKKRRDRINECIAQLKDLLPEHLKLttlghLEKAVVLELTLKHLKALTALTEQQQQKIIALQN 74

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        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1350186531 151 SHSLAERARREKISERMKLLQDLVPGCNKVIGKALVLDEIINYIQSLQHQVEFLSMKLEA 210
Cdd:cd11394     9 AHNAIEKRYRSSINDRIIELKDLVVGPDAKMNKSAVLRKAIDYIRYLQKVNQKLKQENMA 68