ID   KTRA_VIBAL              Reviewed;         220 AA.
AC   O87952;
DT   03-SEP-2014, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1998, sequence version 1.
DT   03-AUG-2022, entry version 86.
DE   RecName: Full=Ktr system potassium uptake protein A;
DE            Short=K(+)-uptake protein KtrA;
GN   Name=ktrA;
OS   Vibrio alginolyticus.
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Vibrionales; Vibrionaceae;
OC   Vibrio.
OX   NCBI_TaxID=663;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, SUBCELLULAR LOCATION, AND GENE
RP   NAME.
RX   PubMed=9642210; DOI=10.1128/jb.180.13.3491-3494.1998;
RA   Nakamura T., Yuda R., Unemoto T., Bakker E.P.;
RT   "KtrAB, a new type of bacterial K(+)-uptake system from Vibrio
RT   alginolyticus.";
RL   J. Bacteriol. 180:3491-3494(1998).
RN   [2]
RP   FUNCTION, AND SUBUNIT.
RX   PubMed=16210320; DOI=10.1074/jbc.m507647200;
RA   Tholema N., Vor der Brueggen M., Maeser P., Nakamura T., Schroeder J.I.,
RA   Kobayashi H., Uozumi N., Bakker E.P.;
RT   "All four putative selectivity filter glycine residues in KtrB are
RT   essential for high affinity and selective K+ uptake by the KtrAB system
RT   from Vibrio alginolyticus.";
RL   J. Biol. Chem. 280:41146-41154(2005).
RN   [3]
RP   FUNCTION, ATP-BINDING, ACTIVITY REGULATION, SUBUNIT, AND SUBCELLULAR
RP   LOCATION.
RX   PubMed=17344221; DOI=10.1074/jbc.m609084200;
RA   Kroening N., Willenborg M., Tholema N., Haenelt I., Schmid R., Bakker E.P.;
RT   "ATP binding to the KTN/RCK subunit KtrA from the K+ -uptake system KtrAB
RT   of Vibrio alginolyticus: its role in the formation of the KtrAB complex and
RT   its requirement in vivo.";
RL   J. Biol. Chem. 282:14018-14027(2007).
CC   -!- FUNCTION: Part of the Na(+)-dependent high affinity K(+) uptake system
CC       KtrAB. KtrA is the regulatory subunit and plays an important role in
CC       the substrate specificity and transport mechanism of the system. Binds
CC       ATP but lacks ATPase activity. {ECO:0000269|PubMed:16210320,
CC       ECO:0000269|PubMed:17344221, ECO:0000269|PubMed:9642210}.
CC   -!- ACTIVITY REGULATION: Requires both ATP and a high membrane potential
CC       for activity. Binding of ATP causes a conformational change in KtrA,
CC       which promotes formation of the KtrAB complex. Can also bind, with
CC       lower affinity, other nucleotides such as NADH or NAD(+), but only ATP
CC       can induce a conformational change. {ECO:0000269|PubMed:17344221}.
CC   -!- SUBUNIT: The uptake system is composed of KtrA and KtrB.
CC       {ECO:0000269|PubMed:16210320, ECO:0000269|PubMed:17344221}.
CC   -!- SUBCELLULAR LOCATION: Cell inner membrane {ECO:0000269|PubMed:17344221,
CC       ECO:0000269|PubMed:9642210}; Peripheral membrane protein
CC       {ECO:0000269|PubMed:17344221, ECO:0000269|PubMed:9642210}; Cytoplasmic
CC       side {ECO:0000269|PubMed:17344221, ECO:0000269|PubMed:9642210}.
CC   -!- SIMILARITY: Belongs to the KtrA potassium transport family.
CC       {ECO:0000305}.
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DR   EMBL; D89592; BAA31234.1; -; Genomic_DNA.
DR   AlphaFoldDB; O87952; -.
DR   SMR; O87952; -.
DR   STRING; 663.BAU10_03570; -.
DR   TCDB; 2.A.38.4.2; the k(+) transporter (trk) family.
DR   eggNOG; COG0569; Bacteria.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0005524; F:ATP binding; IEA:UniProtKB-KW.
DR   GO; GO:0008324; F:cation transmembrane transporter activity; IEA:InterPro.
DR   GO; GO:0006813; P:potassium ion transport; IEA:UniProtKB-KW.
DR   Gene3D; 3.30.70.1450; -; 1.
DR   InterPro; IPR036291; NAD(P)-bd_dom_sf.
DR   InterPro; IPR006037; RCK_C.
DR   InterPro; IPR036721; RCK_C_sf.
DR   InterPro; IPR003148; RCK_N.
DR   Pfam; PF02080; TrkA_C; 1.
DR   Pfam; PF02254; TrkA_N; 1.
DR   SUPFAM; SSF116726; SSF116726; 1.
DR   SUPFAM; SSF51735; SSF51735; 1.
DR   PROSITE; PS51202; RCK_C; 1.
DR   PROSITE; PS51201; RCK_N; 1.
PE   1: Evidence at protein level;
KW   ATP-binding; Cell inner membrane; Cell membrane; Ion transport; Membrane;
KW   Nucleotide-binding; Potassium; Potassium transport; Transport.
FT   CHAIN           1..220
FT                   /note="Ktr system potassium uptake protein A"
FT                   /id="PRO_0000430032"
FT   DOMAIN          7..129
FT                   /note="RCK N-terminal"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00543"
FT   DOMAIN          138..220
FT                   /note="RCK C-terminal"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00544"
FT   BINDING         15
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000250"
FT   BINDING         35..37
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000250"
FT   BINDING         55..56
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000250"
FT   BINDING         77..79
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000250"
FT   BINDING         102..104
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000250"
FT   BINDING         124
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   220 AA;  23806 MW;  239DEA9CD046AD36 CRC64;
     MKTGDKQFAV IGLGRFGLAV CKELQDSGSQ VLAVDINEDR VKEAAGFVSQ AIVANCTHEE
     TVAELKLDDY DMVMIAIGAD VNASILATLI AKEAGVKSVW VKANDRFQAR VLQKIGADHI
     IMPERDMGIR VARKMLDKRV LEFHPLGSGL AMTEFVVGSR LMGKTLSDLA LCKVEGVQVL
     GYKRGPEIIK APDMSTTLEI GDLIIVVGPQ DKLANKLKSL