ID   KAIB_NOSS1              Reviewed;         108 AA.
AC   Q8YT41;
DT   11-OCT-2004, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2002, sequence version 1.
DT   25-MAY-2022, entry version 97.
DE   RecName: Full=Circadian clock protein KaiB;
GN   Name=kaiB; OrderedLocusNames=alr2885;
OS   Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576).
OC   Bacteria; Cyanobacteria; Nostocales; Nostocaceae; Nostoc.
OX   NCBI_TaxID=103690;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=15170179; DOI=10.1038/nsmb781;
RA   Uzumaki T., Fujita M., Nakatsu T., Hayashi F., Shibata H., Itoh N.,
RA   Kato H., Ishiura M.;
RT   "Crystal structure of the C-terminal clock-oscillator domain of the
RT   cyanobacterial KaiA protein.";
RL   Nat. Struct. Mol. Biol. 11:623-631(2004).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=PCC 7120 / SAG 25.82 / UTEX 2576;
RX   PubMed=11759840; DOI=10.1093/dnares/8.5.205;
RA   Kaneko T., Nakamura Y., Wolk C.P., Kuritz T., Sasamoto S., Watanabe A.,
RA   Iriguchi M., Ishikawa A., Kawashima K., Kimura T., Kishida Y., Kohara M.,
RA   Matsumoto M., Matsuno A., Muraki A., Nakazaki N., Shimpo S., Sugimoto M.,
RA   Takazawa M., Yamada M., Yasuda M., Tabata S.;
RT   "Complete genomic sequence of the filamentous nitrogen-fixing
RT   cyanobacterium Anabaena sp. strain PCC 7120.";
RL   DNA Res. 8:205-213(2001).
RN   [3]
RP   X-RAY CRYSTALLOGRAPHY (2.2 ANGSTROMS), HOMODIMERIZATION, INTERACTION WITH
RP   KAIC, AND MUTAGENESIS OF ARG-23.
RX   PubMed=15071498; DOI=10.1038/sj.emboj.7600190;
RA   Garces R.G., Wu N., Gillon W., Pai E.F.;
RT   "Anabaena circadian clock proteins KaiA and KaiB reveal a potential common
RT   binding site to their partner KaiC.";
RL   EMBO J. 23:1688-1698(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 needs the
CC       presence of both KaiA and KaiC, suggesting that it acts by antagonizing
CC       the interaction between KaiA and KaiC (By similarity). {ECO:0000250}.
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 (By similarity). {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the KaiB family. {ECO:0000305}.
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DR   EMBL; AB071284; BAB85868.1; -; Genomic_DNA.
DR   EMBL; BA000019; BAB74584.1; -; Genomic_DNA.
DR   PIR; AF2166; AF2166.
DR   RefSeq; WP_010997036.1; NZ_RSCN01000003.1.
DR   PDB; 1R5P; X-ray; 2.20 A; A/B=1-108.
DR   PDBsum; 1R5P; -.
DR   AlphaFoldDB; Q8YT41; -.
DR   SMR; Q8YT41; -.
DR   STRING; 103690.17131979; -.
DR   EnsemblBacteria; BAB74584; BAB74584; BAB74584.
DR   KEGG; ana:alr2885; -.
DR   eggNOG; COG4251; Bacteria.
DR   OMA; NEFKGVY; -.
DR   OrthoDB; 1999883at2; -.
DR   EvolutionaryTrace; Q8YT41; -.
DR   Proteomes; UP000002483; Chromosome.
DR   GO; GO:0007623; P:circadian rhythm; IEA:UniProtKB-UniRule.
DR   GO; GO:0042326; P:negative regulation of phosphorylation; IEA:InterPro.
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; Reference proteome.
FT   CHAIN           1..108
FT                   /note="Circadian clock protein KaiB"
FT                   /id="PRO_0000217761"
FT   MUTAGEN         23
FT                   /note="R->A: Induces a strong decrease the interaction with
FT                   KaiC."
FT                   /evidence="ECO:0000269|PubMed:15071498"
FT   STRAND          8..16
FT                   /evidence="ECO:0007829|PDB:1R5P"
FT   HELIX           19..36
FT                   /evidence="ECO:0007829|PDB:1R5P"
FT   STRAND          39..46
FT                   /evidence="ECO:0007829|PDB:1R5P"
FT   TURN            47..49
FT                   /evidence="ECO:0007829|PDB:1R5P"
FT   HELIX           62..65
FT                   /evidence="ECO:0007829|PDB:1R5P"
FT   HELIX           66..68
FT                   /evidence="ECO:0007829|PDB:1R5P"
FT   HELIX           71..82
FT                   /evidence="ECO:0007829|PDB:1R5P"
FT   STRAND          87..94
FT                   /evidence="ECO:0007829|PDB:1R5P"
SQ   SEQUENCE   108 AA;  12276 MW;  6DCFFC8184BA28B2 CRC64;
     MNKARKTYVL KLYVAGNTPN SVRALKTLKN ILEQEFQGIY ALKVIDVLKN PQLAEEDKIL
     ATPTLSKILP PPVRKIIGDL SDRERVLIGL DLLYEELTEE DWEAQSNL