KAIB_SYNE7
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 03-AUG-2022, entry version 108.
DE RecName: Full=Circadian clock protein KaiB;
GN Name=kaiB; OrderedLocusNames=Synpcc7942_1217; ORFNames=see0010;
OS Synechococcus elongatus (strain PCC 7942 / FACHB-805) (Anacystis nidulans
OS R2).
OC Bacteria; Cyanobacteria; Synechococcales; Synechococcaceae; Synechococcus.
OX NCBI_TaxID=1140;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, AND MUTANTS KAIB1 AND KAIB2.
RX PubMed=9727980; DOI=10.1126/science.281.5382.1519;
RA Ishiura M., Kutsuna S., Aoki S., Iwasaki H., Andersson C.R., Tanabe A.,
RA Golden S.S., Johnson C.H., Kondo T.;
RT "Expression of a gene cluster kaiABC as a circadian feedback process in
RT 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., McMurtry S.,
RA 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 / FACHB-805;
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 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 KaiC
RT 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 WITH
RP 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., Oyama T.,
RA 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 KaiABC
CC complex may act as a promoter-non-specific transcription regulator that
CC represses transcription, possibly by acting on the state of chromosome
CC compaction. In the complex, it decreases the phosphorylation status of
CC KaiC. It has no effect on KaiC by itself, but instead need the presence
CC of both KaiA and KaiC, suggesting that it acts by antagonizing the
CC interaction between 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 composed
CC of a KaiC homohexamer, a KaiB dimer and two KaiA dimers. The KaiABC
CC complex also interacts with SasA. {ECO:0000269|PubMed:10064581,
CC ECO:0000269|PubMed:12727878, ECO:0000269|PubMed:12727879}.
CC -!- INTERACTION:
CC Q79PF5; Q79PF6: kaiA; NbExp=11; IntAct=EBI-619150, EBI-592281;
CC Q79PF5; Q79PF5: kaiB; NbExp=5; IntAct=EBI-619150, EBI-619150;
CC Q79PF5; Q79PF4: kaiC; NbExp=12; IntAct=EBI-619150, EBI-592287;
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:12727879}. Cell
CC membrane {ECO:0000269|PubMed:12727879}; Peripheral membrane protein
CC {ECO:0000269|PubMed:12727879}. Note=From circadian time (CT) 12-16 to
CC CT 20 the major fraction is membrane-associated, it then translocated
CC to the cytosol, where it probably interacts with KaiC and KaiA.
CC -!- DEVELOPMENTAL STAGE: Accumulates in a circadian fashion, peaking at CT
CC 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}.
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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 AlphaFoldDB; Q79PF5; -.
DR SASBDB; 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; COG4251; Bacteria.
DR HOGENOM; CLU_144073_0_0_3; -.
DR OMA; NEFKGVY; -.
DR OrthoDB; 1999883at2; -.
DR BioCyc; SYNEL:SYNPCC7942_1217-MON; -.
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:UniProtKB-UniRule.
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; Cytoplasm; Membrane.
FT CHAIN 1..102
FT /note="Circadian clock protein KaiB"
FT /id="PRO_0000217767"
FT MUTAGEN 11
FT /note="L->F: In kaiB1; shortens the period of the circadian
FT rhythm to 21 hours."
FT MUTAGEN 74
FT /note="R->W: In kaiB2; shortens the period of the circadian
FT rhythm to 22 hours."
FT STRAND 7..15
FT /evidence="ECO:0007829|PDB:4KSO"
FT HELIX 18..33
FT /evidence="ECO:0007829|PDB:4KSO"
FT TURN 36..38
FT /evidence="ECO:0007829|PDB:4KSO"
FT STRAND 39..45
FT /evidence="ECO:0007829|PDB:4KSO"
FT TURN 46..48
FT /evidence="ECO:0007829|PDB:4KSO"
FT HELIX 61..64
FT /evidence="ECO:0007829|PDB:4KSO"
FT HELIX 70..81
FT /evidence="ECO:0007829|PDB:4KSO"
FT STRAND 86..92
FT /evidence="ECO:0007829|PDB:4KSO"
SQ SEQUENCE 102 AA; 11436 MW; 4E7FD086742A398F CRC64;
MSPRKTYILK LYVAGNTPNS VRALKTLKNI LEVEFQGVYA LKVIDVLKNP QLAEEDKILA
TPTLAKVLPL PVRRIIGDLS DREKVLIGLD LLYGELQDSD DF
