Basic leucine zipper (bZIP) domain of X-box binding protein 1 (XBP1) and similar proteins: a DNA-binding and dimerization domain; XBP1, a member of the Basic leucine zipper (bZIP) family, is the key transcription factor that orchestrates the unfolded protein response (UPR). It is the most conserved component of the UPR and is critical for cell fate determination in response to ER stress. The inositol-requiring enzyme 1 (IRE1)-XBP1 pathway is one of the three major sensors at the ER membrane that initiates the UPR upon activation. IRE1, a type I transmembrane protein kinase and endoribonuclease, oligomerizes upon ER stress leading to its increased activity. It splices the XBP1 mRNA, producing a variant that translocates to the nucleus and activates its target genes, which are involved in protein folding, degradation, and trafficking. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 22026825  81 EEKVQRKKLKNRVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSLQAINESLL 138
Cdd:cd14691   1 EEKDLRRKLKNRVAAQTARDRKKARMDELEERVRELEEENQKLRAENESLRARNEDLL 58

Basic leucine zipper (bZIP) domain of X-box binding protein 1 (XBP1) and similar proteins: a DNA-binding and dimerization domain; XBP1, a member of the Basic leucine zipper (bZIP) family, is the key transcription factor that orchestrates the unfolded protein response (UPR). It is the most conserved component of the UPR and is critical for cell fate determination in response to ER stress. The inositol-requiring enzyme 1 (IRE1)-XBP1 pathway is one of the three major sensors at the ER membrane that initiates the UPR upon activation. IRE1, a type I transmembrane protein kinase and endoribonuclease, oligomerizes upon ER stress leading to its increased activity. It splices the XBP1 mRNA, producing a variant that translocates to the nucleus and activates its target genes, which are involved in protein folding, degradation, and trafficking. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 22026825  81 EEKVQRKKLKNRVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSLQAINESLL 138
Cdd:cd14691   1 EEKDLRRKLKNRVAAQTARDRKKARMDELEERVRELEEENQKLRAENESLRARNEDLL 58

Basic region leucine zipper;

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 22026825    86 RKKLKNRVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSLQA 132
Cdd:pfam07716   4 DRRRKNNEAAKRSREKKKQKEEELEERVKELERENAQLRQKVEQLEK 50

hypothetical protein; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 22026825   65 ASQPKAKKRRLDHLTWEEKVQRKKLKNRVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSLQAINESLLAKNHKL 144
Cdd:PRK12705  35 AERILQEAQKEAEEKLEAALLEAKELLLRERNQQRQEARREREELQREEERLVQKEEQLDARAEKLDNLENQLEEREKAL 114

                         90
                 ....*....|....*..
gi 22026825  145 DSELELLRQELAELKQQ 161
Cdd:PRK12705 115 SARELELEELEKQLDNE 131

Basic leucine zipper (bZIP) domain of X-box binding protein 1 (XBP1) and similar proteins: a DNA-binding and dimerization domain; XBP1, a member of the Basic leucine zipper (bZIP) family, is the key transcription factor that orchestrates the unfolded protein response (UPR). It is the most conserved component of the UPR and is critical for cell fate determination in response to ER stress. The inositol-requiring enzyme 1 (IRE1)-XBP1 pathway is one of the three major sensors at the ER membrane that initiates the UPR upon activation. IRE1, a type I transmembrane protein kinase and endoribonuclease, oligomerizes upon ER stress leading to its increased activity. It splices the XBP1 mRNA, producing a variant that translocates to the nucleus and activates its target genes, which are involved in protein folding, degradation, and trafficking. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 22026825  81 EEKVQRKKLKNRVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSLQAINESLL 138
Cdd:cd14691   1 EEKDLRRKLKNRVAAQTARDRKKARMDELEERVRELEEENQKLRAENESLRARNEDLL 58

Basic leucine zipper (bZIP) domain of bZIP transcription factors: a DNA-binding and dimerization domain; Basic leucine zipper (bZIP) factors comprise one of the most important classes of enhancer-type transcription factors. They act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes including cell survival, learning and memory, lipid metabolism, and cancer progression, among others. They also play important roles in responses to stimuli or stress signals such as cytokines, genotoxic agents, or physiological stresses. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 22026825  85 QRKKLKNRVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSLQAINE 135
Cdd:cd14686   2 ERRRERNREAARRSRERKKERIEELEEEVEELEEENEELKAELEELRAEVE 52

Basic leucine zipper (bZIP) domain of Activating Transcription Factor-4 (ATF-4) and similar proteins: a DNA-binding and dimerization domain; ATF-4 was also isolated and characterized as the cAMP-response element binding protein 2 (CREB2). It is a Basic leucine zipper (bZIP) transcription factor that has been reported to act as both an activator or repressor. It is a critical component in both the unfolded protein response (UPR) and amino acid response (AAR) pathways. Under certain stress conditions, ATF-4 transcription is increased; accumulation of ATF-4 induces the expression of genes involved in amino acid metabolism and transport, mitochondrial function, redox chemistry, and others that ensure protein synthesis and recovery from stress. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|
gi 22026825  82 EKVQRKKLKNRVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSLQ 131
Cdd:cd14692   1 EKKERKREQNKNAATRYRQKKREEKEELLSEEEELEDRNRELKDEVEELQ 50

Basic leucine zipper (bZIP) domain of Plant Elongated/Long Hypocotyl5 (HY5)-like transcription factors and similar proteins: a DNA-binding and dimerization domain; This subfamily is predominantly composed of plant Basic leucine zipper (bZIP) transcription factors with similarity to Solanum lycopersicum and Arabidopsis thaliana HY5. Also included are the Dictyostelium discoideum bZIP transcription factors E and F. HY5 plays an important role in seedling development and is a positive regulator of photomorphogenesis. Plants with decreased levels of HY5 show defects in light responses including inhibited photomorphogenesis, loss of alkaloid organization, and reduced carotenoid accumulation. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 22026825  85 QRKKLKNRVAAQTSRDRKKARMEEmdyeikeltdrteiLQNKCDSLQAINESLLAKNHKLDSE 147
Cdd:cd14704   2 QRRLLRNRESAQLSRQRKKEYLSE--------------LEAKCRELEAENAELEARVELLQAE 50

Basic leucine zipper (bZIP) domain of General control protein GCN4: a DNA-binding and dimerization domain; GCN4 was identified in Saccharomyces cerevisiae from mutations in a deficiency in activation with the general amino acid control pathway. GCN4 encodes a trans-activator of amino acid biosynthetic genes containing 2 acidic activation domains and a C-terminal bZIP domain. In amino acid-deprived cells, GCN4 is up-regulated leading to transcriptional activation of genes encoding amino acid biosynthetic enzymes. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....
gi 22026825  82 EKVQRKKLKNRVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSLQAINE 135
Cdd:cd12193   1 DPVAAKRARNTLAARRSRARKLEEMEELEKRVEELEAENEELKTRAEVLEAEAR 54

Cell division protein ZapB, interacts with FtsZ [Cell cycle control, cell division, chromosome partitioning];

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 22026825 107 EEMDYEIKELTDRTEILQNKCDSLQAINESLLAKNHKLDSELELLRQELAELKQQQQ 163
Cdd:COG3074   7 EELEAKVQQAVDTIELLQMEVEELKEKNEELEQENEELQSENEELQSENEQLKTENA 63

Basic leucine zipper (bZIP) domain of CCAAT/enhancer-binding protein (CEBP) and similar proteins: a DNA-binding and dimerization domain; CEBPs (or C/EBPs) are Basic leucine zipper (bZIP) transcription factors that regulate the cell cycle, differentiation, growth, survival, energy metabolism, innate and adaptive immunity, and inflammation, among others. They are also associated with cancer and viral disease. There are six CEBP proteins in mammalian cells including CEBPA (alpha), CEBPB (beta), CEBPG (gamma), CEBPD (delta), and CEBPE (epsilon), which all contain highly conserved bZIP domains at their C-termini and variations at their N-terminal regions. Each possesses unique properties to regulate cell type-specific growth and differentiation. The sixth isoform, CEBPZ (zeta), lacks an intact DNA-binding domain and is excluded from this subfamily. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 22026825  81 EEKVQRKKlKNRVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSLQ 131
Cdd:cd14693   3 EEYRQKRE-RNNIAVRKSREKAKQRQLETQQKVQELRKENERLQKRVELLT 52

Basic leucine zipper (bZIP) domain of Activating Transcription Factor-2 (ATF-2) and similar proteins: a DNA-binding and dimerization domain; ATF-2 is a sequence-specific DNA-binding protein that belongs to the Basic leucine zipper (bZIP) family of transcription factors. In response to stress, it activates a variety of genes including cyclin A, cyclin D, and c-Jun. ATF-2 also plays a role in the DNA damage response that is independent of its transcriptional activity. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 22026825  85 QRKKL--KNRVAAQTSRDRKKARMEEmdyeikeltdrteiLQNKCDSLQainesllAKNHKLDSELELLRQELAELKQQ 161
Cdd:cd14687   1 KRKRFleRNRIAASKCRQRKKQWVQQ--------------LEEKVRKLE-------SENKALKAEVDKLREEVLDLKNL 58

Basic leucine zipper (bZIP) domain of Cyclic AMP-responsive element-binding protein-like 2 (CREBL2): a DNA-binding and dimerization domain; CREBL2 is a bZIP transcription factor that interacts with CREB and plays a critical role in adipogenesis and lipogenesis. Its overexpression upregulates the expression of PPARgamma and CEBPalpha to promote adipogenesis as well as accelerate lipogenesis by increasing GLUT1 and GLUT4. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*
gi 22026825  83 KVQRKKLKNRVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSLQAINESL 137
Cdd:cd14709   1 KKKAKLERNRQSARESRDRKKLRYQYLEQLVADREREILLLREELEMYKQWCEEL 55

Basic leucine zipper (bZIP) domain of blue light (BL) receptor aureochrome (AUREO) and similar bZIP domains; AUREO is a BL-activated transcription factor specific to phototrophic stramenopiles. It has a bZIP and a BL-sensing light-oxygen voltage (LOV) domain. It has been shown to mediate BL-induced branching and regulate the development of the sex organ in Vaucheria frigida. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription. This subgroup also includes the Epstein-Barr virus (EBV) immediate-early transcription factor ZEBRA (BZLF1, Zta, Z, EB1). ZEBRA exhibits a variant of the bZIP fold, it has a unique dimer interface and a substantial hydrophobic pocket; it has a C-terminal moiety which stabilizes the coiled coil involved in dimer formation. ZEBRA functions to trigger the switch of EBV's biphasic infection cycle from latent to lytic infection. It activates the promoters of EBV lytic genes by binding ZEBRA response elements (ZREs) and inducing a cascade of expression of over 50 viral genes. It also down regulates latency-associated promoters, is an essential replication factor, induces host cell cycle arrest, and alters cellular immune responses and transcription factor activity.

                        10        20        30
                ....*....|....*....|....*....|....*....
gi 22026825  85 QRKKLKNRVAAQTSRDRKKARMEEMDYEIKELTDRTEIL 123
Cdd:cd14809   2 ERRRERNREHARKTRLRKKAYLESLKEQVAALQAENQRL 40

Basic leucine zipper (bZIP) domain of the oncogene Fos (Fos)-like transcription factors: a DNA-binding and dimerization domain; This subfamily is composed of Fos proteins (c-Fos, FosB, Fos-related antigen 1 (Fra-1), and Fra-2), Activating Transcription Factor-3 (ATF-3), and similar proteins. Fos proteins are members of the activator protein-1 (AP-1) complex, which is mainly composed of bZIP dimers of the Jun and Fos families, and to a lesser extent, ATF and musculoaponeurotic fibrosarcoma (Maf) families. The broad combinatorial possibilities for various dimers determine binding specificity, affinity, and the spectrum of regulated genes. The AP-1 complex is implicated in many cell functions including proliferation, apoptosis, survival, migration, tumorigenesis, and morphogenesis, among others. ATF3 is induced by various stress signals such as cytokines, genotoxic agents, or physiological stresses. It is implicated in cancer and host defense against pathogens. It negatively regulates the transcription of pro-inflammatory cytokines and is critical in preventing acute inflammatory syndromes. ATF3 dimerizes with Jun and other ATF proteins; the heterodimers function either as activators or repressors depending on the promoter context. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....
gi 22026825  86 RKKLKNRVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSLQAINESLLA 139
Cdd:cd14699   4 KRRERNKVAAAKCRQRRRELMEELQAEVEQLEDENEKLQSEIANLRSEKEQLEE 57

Uncharacterized conserved protein, contains TOPRIM domain, potential nuclease [General function prediction only];

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|
gi 22026825 112 EIKELTDRTEILQNKCDSLQAINESLLAKNHKLDSELELLRQELAELKQQ 161
Cdd:COG4026 129 EYNELREELLELKEKIDEIAKEKEKLTKENEELESELEELREEYKKLREE 178

Basic leucine zipper (bZIP) domain of CCAAT/enhancer-binding protein beta (CEBPB): a DNA-binding and dimerization domain; CEBPB is a key regulator of metabolism, adipocyte differentiation, myogenesis, and macrophage activation. It is expressed as three distinct isoforms from an intronless gene through alternative translation initiation: CEBPB1 (or liver-enriched activator protein 1, LAP1); CEBPB2 (OR LAP2); and CEBPB3 (or liver-enriched inhibitory protein, LIP). LAP1/2 function as transcriptional activators while LIP is a repressor due to its lack of a transactivation domain. The relative expression of LAP and LIP has effects on inflammation, ER stress, and insulin resistance. CEBPs (or C/EBPs) are Basic leucine zipper (bZIP) transcription factors that regulate many cellular processes. There are six CEBP proteins in mammalian cells including CEBPA (alpha), CEBPB (beta), CEBPG (gamma), CEBPD (delta), and CEBPE (epsilon), which all contain highly conserved bZIP domains at their C-termini and variations at their N-terminal regions. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 22026825  72 KRRLDHLTWEEKVQRKKlkNRVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSL 130
Cdd:cd14712   1 KKTVDKHSDEYKIRRER--NNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQL 57

chromosome segregation protein SMC, common bacterial type; SMC (structural maintenance of chromosomes) proteins bind DNA and act in organizing and segregating chromosomes for partition. SMC proteins are found in bacteria, archaea, and eukaryotes. This family represents the SMC protein of most bacteria. The smc gene is often associated with scpB (TIGR00281) and scpA genes, where scp stands for segregation and condensation protein. SMC was shown (in Caulobacter crescentus) to be induced early in S phase but present and bound to DNA throughout the cell cycle. [Cellular processes, Cell division, DNA metabolism, Chromosome-associated proteins]

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 22026825     69 KAKKRRLDHltwEEKVQRKKLKN----RVAAQTSRDRKKARMEEMDYEIKELTDRTEILQNKCDSLQAINESLLAK---- 140
Cdd:TIGR02168  294 ANEISRLEQ---QKQILRERLANlerqLEELEAQLEELESKLDELAEELAELEEKLEELKEELESLEAELEELEAEleel 370

                           90       100
                   ....*....|....*....|....*.
gi 22026825    141 ---NHKLDSELELLRQELAELKQQQQ 163
Cdd:TIGR02168  371 esrLEELEEQLETLRSKVAQLELQIA 396