ID   FLK_SALTY               Reviewed;         333 AA.
AC   Q7CQ37; Q79BI3;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   03-AUG-2022, entry version 83.
DE   RecName: Full=Flagellar regulator flk;
DE   AltName: Full=Fluke;
GN   Name=flk; OrderedLocusNames=STM2371;
OS   Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Enterobacteriaceae; Salmonella.
OX   NCBI_TaxID=99287;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], GENE NAME, AND FUNCTION.
RX   PubMed=9079927; DOI=10.1128/jb.179.7.2389-2400.1997;
RA   Karlinsey J.E., Pease A.J., Winkler M.E., Bailey J.L., Hughes K.T.;
RT   "The flk gene of Salmonella typhimurium couples flagellar P- and L-ring
RT   assembly to flagellar morphogenesis.";
RL   J. Bacteriol. 179:2389-2400(1997).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=LT2 / SGSC1412 / ATCC 700720;
RX   PubMed=11677609; DOI=10.1038/35101614;
RA   McClelland M., Sanderson K.E., Spieth J., Clifton S.W., Latreille P.,
RA   Courtney L., Porwollik S., Ali J., Dante M., Du F., Hou S., Layman D.,
RA   Leonard S., Nguyen C., Scott K., Holmes A., Grewal N., Mulvaney E.,
RA   Ryan E., Sun H., Florea L., Miller W., Stoneking T., Nhan M., Waterston R.,
RA   Wilson R.K.;
RT   "Complete genome sequence of Salmonella enterica serovar Typhimurium LT2.";
RL   Nature 413:852-856(2001).
RN   [3]
RP   FUNCTION IN FLAGELLA ASSEMBLY.
RX   PubMed=9765570; DOI=10.1128/jb.180.20.5384-5397.1998;
RA   Karlinsey J.E., Tsui H.-C., Winkler M.E., Hughes K.T.;
RT   "Flk couples flgM translation to flagellar ring assembly in Salmonella
RT   typhimurium.";
RL   J. Bacteriol. 180:5384-5397(1998).
RN   [4]
RP   FUNCTION IN FLGM REGULATION.
RX   PubMed=16629666; DOI=10.1111/j.1365-2958.2006.05135.x;
RA   Aldridge P., Karlinsey J.E., Becker E., Chevance F.F., Hughes K.T.;
RT   "Flk prevents premature secretion of the anti-sigma factor FlgM into the
RT   periplasm.";
RL   Mol. Microbiol. 60:630-643(2006).
RN   [5]
RP   FUNCTION.
RX   PubMed=19376867; DOI=10.1128/jb.01811-08;
RA   Hirano T., Mizuno S., Aizawa S., Hughes K.T.;
RT   "Mutations in flk, flgG, flhA, and flhE that affect the flagellar type III
RT   secretion specificity switch in Salmonella enterica.";
RL   J. Bacteriol. 191:3938-3949(2009).
CC   -!- FUNCTION: Acts as a regulator of flagellar gene expression by
CC       modulating the protein level of the anti sigma factor FlgM upon sensing
CC       ring completion or hook elongation. Flk could inhibit FlgM secretion by
CC       acting as a braking system for the flagellar-associated type III
CC       secretion (T3S) system. Plays a role in hindering to flip the flagellar
CC       T3S specificity switch from the rod and hook-type substrates to
CC       filament-type substrates prior to hook-basal body (HBB) completion
CC       possibly by preventing interaction of FliK with FlhB.
CC       {ECO:0000269|PubMed:16629666, ECO:0000269|PubMed:19376867,
CC       ECO:0000269|PubMed:9079927, ECO:0000269|PubMed:9765570}.
CC   -!- SUBCELLULAR LOCATION: Cell inner membrane {ECO:0000305}; Single-pass
CC       membrane protein {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the flk family. {ECO:0000305}.
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DR   EMBL; U77618; AAB51501.1; -; Genomic_DNA.
DR   EMBL; AE006468; AAL21272.1; -; Genomic_DNA.
DR   RefSeq; NP_461313.1; NC_003197.2.
DR   RefSeq; WP_000553395.1; NC_003197.2.
DR   AlphaFoldDB; Q7CQ37; -.
DR   STRING; 99287.STM2371; -.
DR   PaxDb; Q7CQ37; -.
DR   PRIDE; Q7CQ37; -.
DR   EnsemblBacteria; AAL21272; AAL21272; STM2371.
DR   GeneID; 1253893; -.
DR   KEGG; stm:STM2371; -.
DR   PATRIC; fig|99287.12.peg.2510; -.
DR   HOGENOM; CLU_063700_0_0_6; -.
DR   OMA; FTHLVTW; -.
DR   PhylomeDB; Q7CQ37; -.
DR   BioCyc; SENT99287:STM2371-MON; -.
DR   Proteomes; UP000001014; Chromosome.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0010468; P:regulation of gene expression; IEA:InterPro.
DR   InterPro; IPR023597; Flagellar_regulator_Flk.
DR   PIRSF; PIRSF020588; Flk; 1.
PE   1: Evidence at protein level;
KW   Cell inner membrane; Cell membrane; Membrane; Reference proteome;
KW   Transmembrane; Transmembrane helix.
FT   CHAIN           1..333
FT                   /note="Flagellar regulator flk"
FT                   /id="PRO_0000315226"
FT   TOPO_DOM        1..311
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        312..332
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        333
FT                   /note="Periplasmic"
FT                   /evidence="ECO:0000255"
FT   REGION          1..27
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   333 AA;  37056 MW;  263FF20F73107F98 CRC64;
     MHPISGAPAQ PPGEGRNPLS AASEQPLSMQ QRTVLERLIT RLISLTQQQS AEVWAGMKHD
     LGIKNDAPLL SRHFPAAEQN LTQRLGVAQQ NHANRQVLSQ LTELLGVGNN RQAVSDFIRQ
     QYGQTALSQL TPDQLKNVLT LLQQGQLSIP QPQQRPATDR PLLPAEHNTL NQLVTKLAAA
     TGESNKLIWQ SMLELSGVKS GELIPAKQFT HLATWLQARQ TLSLQHAPTL HTLQAALKQP
     LEPDELTAIK EYAQHTYQIQ PQTVLTTAQV QDLLNHIFLR RVEREADELE PLSIQPIYRP
     FAPMIETVKN LSARPGLLFI ALIIVLALFW LVS