KAIC_THELV
ID KAIC_THELV Reviewed; 541 AA.
AC Q8GGL1;
DT 11-OCT-2004, integrated into UniProtKB/Swiss-Prot.
DT 01-MAR-2003, sequence version 1.
DT 03-AUG-2022, entry version 73.
DE RecName: Full=Circadian clock protein kinase KaiC {ECO:0000255|HAMAP-Rule:MF_01836};
DE EC=2.7.11.1 {ECO:0000255|HAMAP-Rule:MF_01836};
GN Name=kaiC {ECO:0000255|HAMAP-Rule:MF_01836};
OS Thermostichus lividus (Synechococcus lividus).
OC Bacteria; Cyanobacteria; Thermostichales; Thermostichaceae; Thermostichus.
OX NCBI_TaxID=33070;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], HEXAMERIZATION, AND DNA-BINDING.
RC STRAIN=P2;
RX PubMed=12477935; DOI=10.1073/pnas.262578499;
RA Mori T., Saveliev S.V., Xu Y., Stafford W.F., Cox M.M., Inman R.B.,
RA Johnson C.H.;
RT "Circadian clock protein KaiC forms ATP-dependent hexameric rings and binds
RT DNA.";
RL Proc. Natl. Acad. Sci. U.S.A. 99:17203-17208(2002).
CC -!- FUNCTION: Core component of the KaiABC clock protein complex, which
CC constitutes the main circadian regulator in cyanobacteria. Binds to
CC DNA. The KaiABC complex may act as a promoter-nonspecific transcription
CC regulator that represses transcription, possibly by acting on the state
CC of chromosome compaction. {ECO:0000255|HAMAP-Rule:MF_01836}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-
CC [protein]; Xref=Rhea:RHEA:17989, Rhea:RHEA-COMP:9863, Rhea:RHEA-
CC COMP:11604, ChEBI:CHEBI:15378, ChEBI:CHEBI:29999, ChEBI:CHEBI:30616,
CC ChEBI:CHEBI:83421, ChEBI:CHEBI:456216; EC=2.7.11.1;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_01836};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-
CC threonyl-[protein]; Xref=Rhea:RHEA:46608, Rhea:RHEA-COMP:11060,
CC Rhea:RHEA-COMP:11605, ChEBI:CHEBI:15378, ChEBI:CHEBI:30013,
CC ChEBI:CHEBI:30616, ChEBI:CHEBI:61977, ChEBI:CHEBI:456216;
CC EC=2.7.11.1; Evidence={ECO:0000255|HAMAP-Rule:MF_01836};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_01836};
CC -!- ACTIVITY REGULATION: The interaction with KaiA enhances its
CC phosphorylation status, while the interaction with KaiB decreases it. A
CC KaiA dimer is sufficient to enhance KaiC phosphorylation.
CC {ECO:0000255|HAMAP-Rule:MF_01836}.
CC -!- SUBUNIT: Homohexamer; hexamerization is dependent on ATP-binding. Core
CC component of the KaiABC complex, at least composed of a KaiC
CC homohexamer, a KaiB dimer and two KaiA dimers. Interacts directly with
CC SasA. {ECO:0000255|HAMAP-Rule:MF_01836}.
CC -!- DOMAIN: The KaiC domains mediate the interaction with KaiA.
CC {ECO:0000255|HAMAP-Rule:MF_01836}.
CC -!- PTM: Phosphorylated on serine/threonine residues by autocatalysis. Both
CC phosphorylated and unphosphorylated forms exist. Can probably
CC autophosphorylate and autodephosphorylate. Phosphorylated form
CC correlates with clock speed. {ECO:0000255|HAMAP-Rule:MF_01836}.
CC -!- SIMILARITY: Belongs to the KaiC family. {ECO:0000255|HAMAP-
CC Rule:MF_01836}.
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DR EMBL; AF497977; AAO12971.1; -; Genomic_DNA.
DR AlphaFoldDB; Q8GGL1; -.
DR SMR; Q8GGL1; -.
DR GO; GO:0005524; F:ATP binding; IEA:UniProtKB-UniRule.
DR GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR GO; GO:0000287; F:magnesium ion binding; IEA:UniProtKB-UniRule.
DR GO; GO:0106310; F:protein serine kinase activity; IEA:RHEA.
DR GO; GO:0004674; F:protein serine/threonine kinase activity; IEA:UniProtKB-KW.
DR GO; GO:0004712; F:protein serine/threonine/tyrosine kinase activity; IEA:UniProtKB-UniRule.
DR GO; GO:0007623; P:circadian rhythm; IEA:UniProtKB-UniRule.
DR GO; GO:0016310; P:phosphorylation; IEA:UniProtKB-KW.
DR GO; GO:0042752; P:regulation of circadian rhythm; IEA:InterPro.
DR GO; GO:0006355; P:regulation of transcription, DNA-templated; IEA:InterPro.
DR Gene3D; 3.40.50.300; -; 2.
DR HAMAP; MF_01836; KaiC; 1.
DR InterPro; IPR013503; Circadian_KaiC_bact.
DR InterPro; IPR030665; KaiC.
DR InterPro; IPR014774; KaiC-like_dom.
DR InterPro; IPR010624; KaiC_dom.
DR InterPro; IPR027417; P-loop_NTPase.
DR Pfam; PF06745; ATPase; 2.
DR PIRSF; PIRSF039117; KaiC; 1.
DR SUPFAM; SSF52540; SSF52540; 2.
DR TIGRFAMs; TIGR02655; circ_KaiC; 1.
DR PROSITE; PS51146; KAIC; 2.
PE 1: Evidence at protein level;
KW ATP-binding; Biological rhythms; DNA-binding; Kinase; Magnesium;
KW Metal-binding; Nucleotide-binding; Phosphoprotein; Repeat; Repressor;
KW Serine/threonine-protein kinase; Transcription; Transcription regulation;
KW Transferase.
FT CHAIN 1..541
FT /note="Circadian clock protein kinase KaiC"
FT /id="PRO_0000217780"
FT DOMAIN 40..281
FT /note="KaiC 1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01836"
FT DOMAIN 282..514
FT /note="KaiC 2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01836"
FT REGION 1..40
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 13..37
FT /note="Basic and acidic residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT BINDING 67..74
FT /ligand="ATP"
FT /ligand_id="ChEBI:CHEBI:30616"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01836"
FT BINDING 309..316
FT /ligand="ATP"
FT /ligand_id="ChEBI:CHEBI:30616"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01836"
FT BINDING 316
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01836"
FT BINDING 339
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01836"
FT BINDING 340
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01836"
FT BINDING 399
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01836"
FT MOD_RES 453
FT /note="Phosphothreonine; by autocatalysis"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01836"
SQ SEQUENCE 541 AA; 60284 MW; 3FB865423396C33B CRC64;
MNQSLGPSEP EKPQDNTAED STEPTPDNHR ADLSELRGIP KKQTGIEGFE DISHGGLPLG
RTTLVSGTSG TGKTLFAMQF LYNGIVKYQE PGIFVTFEET PADIIRNASS FGWDLQALID
RGQLFILDAS PDPEGYEVSG NFDLSALIER IQYAIRKYKA KRVSIDSVTA IFQQYDPAGV
VRRELFRLTA RLKQANVTTV MTTERTDEYG PIARYGVEEF VSDNVVILRN ILEGEKRRRT
IEILKLRGTT HMKGEYPFTI TNDGINIFPL GAMQLTQRSS NVRVSSGIEK LDEMCGGGFF
KDSIILATGA TGTGKTSLVS KFLERGCLDG ERCILFAYEE SRAQLSRNAS SWGIDLEEFE
RQGLLKIICA YPESAGLEDH LQKIKTEMMA FKPSRMAIDS LSALARGVSQ NAFRQFVIGV
TGLAKQEEIT GFFTNTTDQF MGSHSITESH ISTITDTIIL LQYVEIRGEM ARALNVFKMR
GSWHDKGIRE YLISNAGIQI RDSFRGYERI ISGSPTRINV DEKNELSRIV QNVQALEEEG
L
