ID KAIB_SYNE7 Reviewed; 102 AA. AC Q79PF5; Q31NX2; Q9Z3H3; DT 11-OCT-2004, integrated into UniProtKB/Swiss-Prot. DT 05-JUL-2004, sequence version 1. DT 18-JUL-2018, entry version 91. DE RecName: Full=Circadian clock protein KaiB; GN Name=kaiB; OrderedLocusNames=Synpcc7942_1217; ORFNames=see0010; OS Synechococcus elongatus (strain PCC 7942) (Anacystis nidulans R2). OC Bacteria; Cyanobacteria; Synechococcales; Synechococcaceae; OC Synechococcus. OX NCBI_TaxID=1140; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, AND MUTANTS KAIB1 AND RP KAIB2. RX PubMed=9727980; DOI=10.1126/science.281.5382.1519; RA Ishiura M., Kutsuna S., Aoki S., Iwasaki H., Andersson C.R., RA Tanabe A., Golden S.S., Johnson C.H., Kondo T.; RT "Expression of a gene cluster kaiABC as a circadian feedback process RT in cyanobacteria."; RL Science 281:1519-1523(1998). RN [2] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RA Holtman C.K., Sandoval P., Chen Y., Socias T., Mohler B.J., RA McMurtry S., Gonzalez A., Salinas I., Golden S.S., Youderian P.; RT "Synechococcus elongatus PCC7942 cosmid 7G3."; RL Submitted (JUN-2002) to the EMBL/GenBank/DDBJ databases. RN [3] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=PCC 7942; RG US DOE Joint Genome Institute; RA Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C., Glavina T., RA Hammon N., Israni S., Pitluck S., Schmutz J., Larimer F., Land M., RA Kyrpides N., Lykidis A., Richardson P.; RT "Complete sequence of chromosome 1 of Synechococcus elongatus PCC RT 7942."; RL Submitted (AUG-2005) to the EMBL/GenBank/DDBJ databases. RN [4] RP HOMODIMERIZATION, AND INTERACTION WITH KAIA AND KAIC. RX PubMed=10064581; DOI=10.1093/emboj/18.5.1137; RA Iwasaki H., Taniguchi Y., Ishiura M., Kondo T.; RT "Physical interactions among circadian clock proteins KaiA, KaiB and RT KaiC in cyanobacteria."; RL EMBO J. 18:1137-1145(1999). RN [5] RP FUNCTION, AND INTERACTION WITH KAIC. RX PubMed=12727878; DOI=10.1093/emboj/cdg168; RA Xu Y., Mori T., Johnson C.H.; RT "Cyanobacterial circadian clockwork: roles of KaiA, KaiB and the kaiBC RT promoter in regulating KaiC."; RL EMBO J. 22:2117-2126(2003). RN [6] RP FUNCTION, DEVELOPMENTAL STAGE, SUBCELLULAR LOCATION, AND INTERACTION RP WITH KAIC. RX PubMed=12727879; DOI=10.1093/emboj/cdg212; RA Kitayama Y., Iwasaki H., Nishiwaki T., Kondo T.; RT "KaiB functions as an attenuator of KaiC phosphorylation in the RT cyanobacterial circadian clock system."; RL EMBO J. 22:2127-2134(2003). RN [7] RP FUNCTION OF THE KAIABC COMPLEX, AND INDUCTION. RX PubMed=14709675; DOI=10.1073/pnas.0307411100; RA Nakahira Y., Katayama M., Miyashita H., Kutsuna S., Iwasaki H., RA Oyama T., Kondo T.; RT "Global gene repression by KaiC as a master process of prokaryotic RT circadian system."; RL Proc. Natl. Acad. Sci. U.S.A. 101:881-885(2004). CC -!- FUNCTION: Component of the KaiABC clock protein complex, which CC constitutes the main circadian regulator in cyanobacteria. The CC KaiABC complex may act as a promoter-non-specific transcription CC regulator that represses transcription, possibly by acting on the CC state of chromosome compaction. In the complex, it decreases the CC phosphorylation status of KaiC. It has no effect on KaiC by CC itself, but instead need the presence of both KaiA and KaiC, CC suggesting that it acts by antagonizing the interaction between CC KaiA and KaiC. {ECO:0000269|PubMed:12727878, CC ECO:0000269|PubMed:12727879, ECO:0000269|PubMed:14709675, CC ECO:0000269|PubMed:9727980}. CC -!- SUBUNIT: Homodimer. Component of the KaiABC complex, at least CC composed of a KaiC homohexamer, a KaiB dimer and two KaiA dimers. CC The KaiABC complex also interacts with SasA. CC {ECO:0000269|PubMed:10064581, ECO:0000269|PubMed:12727878, CC ECO:0000269|PubMed:12727879}. CC -!- INTERACTION: CC Self; NbExp=5; IntAct=EBI-619150, EBI-619150; CC Q79PF6:kaiA; NbExp=11; IntAct=EBI-619150, EBI-592281; CC Q79PF4:kaiC; NbExp=12; IntAct=EBI-619150, EBI-592287; CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:12727879}. CC Cell membrane {ECO:0000269|PubMed:12727879}; Peripheral membrane CC protein {ECO:0000269|PubMed:12727879}. Note=From circadian time CC (CT) 12-16 to CT 20 the major fraction is membrane-associated, it CC then translocated to the cytosol, where it probably interacts with CC KaiC and KaiA. CC -!- DEVELOPMENTAL STAGE: Accumulates in a circadian fashion, peaking CC at CT 15-18. {ECO:0000269|PubMed:12727879}. CC -!- INDUCTION: Down-regulated by KaiC. {ECO:0000269|PubMed:14709675}. CC -!- MISCELLANEOUS: 'Kai' means 'cycle' in Japanese. CC -!- SIMILARITY: Belongs to the KaiB family. {ECO:0000305}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; AB010691; BAA37102.1; -; Genomic_DNA. DR EMBL; AY120853; AAM82685.1; -; Genomic_DNA. DR EMBL; CP000100; ABB57247.1; -; Genomic_DNA. DR PIR; T44268; T44268. DR RefSeq; WP_011242647.1; NC_007604.1. DR PDB; 4KSO; X-ray; 2.62 A; A/B/C/D=1-102. DR PDB; 5N8Y; EM; 4.70 A; G/H/I/J/K/L=1-102. DR PDBsum; 4KSO; -. DR PDBsum; 5N8Y; -. DR ProteinModelPortal; Q79PF5; -. DR SMR; Q79PF5; -. DR DIP; DIP-33331N; -. DR IntAct; Q79PF5; 2. DR STRING; 1140.Synpcc7942_1217; -. DR PRIDE; Q79PF5; -. DR EnsemblBacteria; ABB57247; ABB57247; Synpcc7942_1217. DR KEGG; syf:Synpcc7942_1217; -. DR eggNOG; ENOG4108ZGN; Bacteria. DR eggNOG; ENOG4111NNQ; LUCA. DR HOGENOM; HOG000230415; -. DR KO; K08481; -. DR OrthoDB; POG091H14Y8; -. DR BioCyc; SYNEL:SYNPCC7942_1217-MONOMER; -. DR Proteomes; UP000002717; Chromosome. DR GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell. DR GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell. DR GO; GO:0042802; F:identical protein binding; IPI:IntAct. DR GO; GO:0007623; P:circadian rhythm; IEA:InterPro. DR GO; GO:0009649; P:entrainment of circadian clock; IDA:UniProtKB. DR GO; GO:0042326; P:negative regulation of phosphorylation; IDA:CACAO. DR GO; GO:0042752; P:regulation of circadian rhythm; IMP:CACAO. DR CDD; cd02978; KaiB_like; 1. DR HAMAP; MF_01835; KaiB; 1. DR InterPro; IPR013474; Circ_KaiB. DR InterPro; IPR039022; KaiB-like. DR InterPro; IPR011649; KaiB_domain. DR InterPro; IPR036249; Thioredoxin-like_sf. DR PANTHER; PTHR41709; PTHR41709; 1. DR Pfam; PF07689; KaiB; 1. DR SMART; SM01248; KaiB; 1. DR SUPFAM; SSF52833; SSF52833; 1. DR TIGRFAMs; TIGR02654; circ_KaiB; 1. PE 1: Evidence at protein level; KW 3D-structure; Biological rhythms; Cell membrane; Complete proteome; KW Cytoplasm; Membrane; Reference proteome. FT CHAIN 1 102 Circadian clock protein KaiB. FT /FTId=PRO_0000217767. FT MUTAGEN 11 11 L->F: In kaiB1; shortens the period of FT the circadian rhythm to 21 hours. FT MUTAGEN 74 74 R->W: In kaiB2; shortens the period of FT the circadian rhythm to 22 hours. FT STRAND 7 15 {ECO:0000244|PDB:4KSO}. FT HELIX 18 33 {ECO:0000244|PDB:4KSO}. FT TURN 36 38 {ECO:0000244|PDB:4KSO}. FT STRAND 39 45 {ECO:0000244|PDB:4KSO}. FT TURN 46 48 {ECO:0000244|PDB:4KSO}. FT HELIX 61 64 {ECO:0000244|PDB:4KSO}. FT HELIX 70 81 {ECO:0000244|PDB:4KSO}. FT STRAND 86 92 {ECO:0000244|PDB:4KSO}. SQ SEQUENCE 102 AA; 11436 MW; 4E7FD086742A398F CRC64; MSPRKTYILK LYVAGNTPNS VRALKTLKNI LEVEFQGVYA LKVIDVLKNP QLAEEDKILA TPTLAKVLPL PVRRIIGDLS DREKVLIGLD LLYGELQDSD DF //