ID   KAIA_THEVL              Reviewed;         283 AA.
AC   Q6L8K1;
DT   11-OCT-2004, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   25-MAY-2022, entry version 59.
DE   RecName: Full=Circadian clock protein KaiA;
GN   Name=kaiA;
OS   Thermostichus vulcanus (Synechococcus vulcanus).
OC   Bacteria; Cyanobacteria; Thermostichales; Thermostichaceae; Thermostichus.
OX   NCBI_TaxID=32053;
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).
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-nonspecific transcription regulator that
CC       represses transcription, possibly by acting on the state of chromosome
CC       compaction. In the complex, it enhances the phosphorylation status of
CC       KaiC. In contrast, the presence of KaiB in the complex decreases the
CC       phosphorylation status of KaiC, suggesting that KaiB acts by
CC       antagonizing the interaction between KaiA and KaiC. A KaiA dimer is
CC       sufficient to enhance KaiC hexamer phosphorylation (By similarity).
CC       {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   -!- INTERACTION:
CC       Q6L8K1; Q6L8J9: kaiC; NbExp=2; IntAct=EBI-934195, EBI-934214;
CC   -!- DOMAIN: The KaiA domain mediates the interaction with KaiC, the
CC       homodimerization, and is responsible for the clock oscillation
CC       function. {ECO:0000250}.
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DR   EMBL; AB121971; BAD21221.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q6L8K1; -.
DR   BMRB; Q6L8K1; -.
DR   SMR; Q6L8K1; -.
DR   IntAct; Q6L8K1; 1.
DR   MINT; Q6L8K1; -.
DR   EvolutionaryTrace; Q6L8K1; -.
DR   GO; GO:0007623; P:circadian rhythm; IEA:InterPro.
DR   GO; GO:0006468; P:protein phosphorylation; IEA:InterPro.
DR   Gene3D; 1.10.1240.30; -; 1.
DR   InterPro; IPR011006; CheY-like_superfamily.
DR   InterPro; IPR011648; Circadian_clock_KaiA.
DR   InterPro; IPR020844; Circadian_clock_KaiA_N.
DR   InterPro; IPR020856; Circadian_clock_protein_KaiA_C.
DR   InterPro; IPR017944; KaiA/RbsU_helical_domain_sf.
DR   Pfam; PF07688; KaiA; 1.
DR   SMART; SM01247; KaiA; 1.
DR   SUPFAM; SSF101215; SSF101215; 1.
DR   SUPFAM; SSF52172; SSF52172; 1.
DR   PROSITE; PS51431; KAIA_C; 1.
DR   PROSITE; PS51430; KAIA_N; 1.
PE   1: Evidence at protein level;
KW   Biological rhythms.
FT   CHAIN           1..283
FT                   /note="Circadian clock protein KaiA"
FT                   /id="PRO_0000217873"
FT   DOMAIN          3..163
FT                   /note="KaiA N-terminal"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00760"
FT   DOMAIN          173..281
FT                   /note="KaiA C-terminal"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00761"
SQ   SEQUENCE   283 AA;  32354 MW;  2BC455DB1C016A6F CRC64;
     MAQSTALTIC GLVYSPAIGQ ELVRLHTSDI DELVYFSSER EFCNYLEARR NSVACLILEW
     GEGTPQIITY LHHSATLLPA ILIFPAAPAP PPAGPHYHIA EVILTTDQLD QLNRQIEEAI
     TGFVKLCPGC AVPPHVLFRL PALKESSNVD PQHRLSQKLK ERLGYLGVYY KRDTAFFFRR
     MSPADKRKLL DELRSIYRTI VLEYFNTDAK VNERIDEFVS KAFFADISVS QVLEIHVELM
     DTFSKQLKLE GRSEDILLDY RLTLIDVIAH LCEMYRRSIP REV