ID   HFLK_ECOLI              Reviewed;         419 AA.
AC   P0ABC7; P25662; Q2M6D1;
DT   08-NOV-2005, integrated into UniProtKB/Swiss-Prot.
DT   08-NOV-2005, sequence version 1.
DT   05-OCT-2016, entry version 87.
DE   RecName: Full=Modulator of FtsH protease HflK;
GN   Name=hflK; Synonyms=hflA; OrderedLocusNames=b4174, JW4132;
OS   Escherichia coli (strain K12).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacteriales;
OC   Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=83333;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=8248183; DOI=10.1073/pnas.90.22.10866;
RA   Noble J.A., Innis M.A., Koonin E.V., Rudd K.E., Banuett F.,
RA   Herskowitz I.;
RT   "The Escherichia coli hflA locus encodes a putative GTP-binding
RT   protein and two membrane proteins, one of which contains a protease-
RT   like domain.";
RL   Proc. Natl. Acad. Sci. U.S.A. 90:10866-10870(1993).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / MG1655 / ATCC 47076;
RX   PubMed=7610040; DOI=10.1093/nar/23.12.2105;
RA   Burland V.D., Plunkett G. III, Sofia H.J., Daniels D.L.,
RA   Blattner F.R.;
RT   "Analysis of the Escherichia coli genome VI: DNA sequence of the
RT   region from 92.8 through 100 minutes.";
RL   Nucleic Acids Res. 23:2105-2119(1995).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / MG1655 / ATCC 47076;
RX   PubMed=9278503; DOI=10.1126/science.277.5331.1453;
RA   Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V.,
RA   Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F.,
RA   Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J.,
RA   Mau B., Shao Y.;
RT   "The complete genome sequence of Escherichia coli K-12.";
RL   Science 277:1453-1462(1997).
RN   [4]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / W3110 / ATCC 27325 / DSM 5911;
RX   PubMed=16738553; DOI=10.1038/msb4100049;
RA   Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S.,
RA   Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T.;
RT   "Highly accurate genome sequences of Escherichia coli K-12 strains
RT   MG1655 and W3110.";
RL   Mol. Syst. Biol. 2:E1-E5(2006).
RN   [5]
RP   CHARACTERIZATION.
RX   PubMed=3040675;
RA   Banuett F., Herskowitz I.;
RT   "Identification of polypeptides encoded by an Escherichia coli locus
RT   (hflA) that governs the lysis-lysogeny decision of bacteriophage
RT   lambda.";
RL   J. Bacteriol. 169:4076-4085(1987).
RN   [6]
RP   INTERACTION WITH HFLC, AND SUGGESTION OF PROTEASE ACTIVITY.
RC   STRAIN=W3102, and X9368;
RX   PubMed=2973057; DOI=10.1073/pnas.85.21.7882;
RA   Cheng H.H., Muhlrad P.J., Hoyt M.A., Echols H.;
RT   "Cleavage of the cII protein of phage lambda by purified HflA
RT   protease: control of the switch between lysis and lysogeny.";
RL   Proc. Natl. Acad. Sci. U.S.A. 85:7882-7886(1988).
RN   [7]
RP   FUNCTION, INTERACTION WITH HFLC AND FTSH, SUBCELLULAR LOCATION, AND
RP   MUTAGENESIS OF ALA-145.
RC   STRAIN=K12 / CSH26 / AD16;
RX   PubMed=8947034;
RA   Kihara A., Akiyama Y., Ito K.;
RT   "A protease complex in the Escherichia coli plasma membrane: HflKC
RT   (HflA) forms a complex with FtsH (HflB), regulating its proteolytic
RT   activity against SecY.";
RL   EMBO J. 15:6122-6131(1996).
RN   [8]
RP   TOPOLOGY, AND LACK OF PROTEASE ACTIVITY.
RC   STRAIN=K12 / CSH26 / AD16;
RX   PubMed=9159109; DOI=10.1073/pnas.94.11.5544;
RA   Kihara A., Akiyama Y., Ito K.;
RT   "Host regulation of lysogenic decision in bacteriophage lambda:
RT   transmembrane modulation of FtsH (HflB), the cII degrading protease,
RT   by HflKC (HflA).";
RL   Proc. Natl. Acad. Sci. U.S.A. 94:5544-5549(1997).
RN   [9]
RP   INSTABILITY IN THE ABSENCE OF HFLC, AND MEMBRANE TRANSLOCATION
RP   MECHANISM.
RC   STRAIN=K12 / CSH26 / AD16, and K12 / MC4100;
RX   PubMed=9792691; DOI=10.1074/jbc.273.45.29770;
RA   Kihara A., Ito K.;
RT   "Translocation, folding, and stability of the HflKC complex with
RT   signal anchor topogenic sequences.";
RL   J. Biol. Chem. 273:29770-29775(1998).
RN   [10]
RP   INTERACTION WITH YCCA.
RC   STRAIN=K12 / CSH26 / AD16;
RX   PubMed=9636708; DOI=10.1006/jmbi.1998.1781;
RA   Kihara A., Akiyama Y., Ito K.;
RT   "Different pathways for protein degradation by the FtsH/HflKC
RT   membrane-embedded protease complex: an implication from the
RT   interference by a mutant form of a new substrate protein, YccA.";
RL   J. Mol. Biol. 279:175-188(1998).
RN   [11]
RP   REVIEW.
RX   PubMed=19454621; DOI=10.1093/jb/mvp071;
RA   Akiyama Y.;
RT   "Quality control of cytoplasmic membrane proteins in Escherichia
RT   coli.";
RL   J. Biochem. 146:449-454(2009).
CC   -!- FUNCTION: HflC and HflK help govern the stability of phage lambda
CC       cII protein, and thereby control the lysogenization frequency of
CC       phage lambda. HflKC inhibits the SecY-degrading activity of FtsH,
CC       possibly helping quality control of integral membrane proteins.
CC       {ECO:0000269|PubMed:8947034}.
CC   -!- SUBUNIT: HflC and HflK interact to form a complex, originally
CC       called HflA, now called HflKC. HflKC interacts with FtsH; complex
CC       formation is stimulated by ATP, and with YccA.
CC       {ECO:0000269|PubMed:2973057, ECO:0000269|PubMed:8947034,
CC       ECO:0000269|PubMed:9636708}.
CC   -!- SUBCELLULAR LOCATION: Cell inner membrane
CC       {ECO:0000269|PubMed:8947034}; Single-pass type II membrane protein
CC       {ECO:0000269|PubMed:8947034}.
CC   -!- MISCELLANEOUS: Integration of this protein into the membrane
CC       depends on SecA, SecY and SecD but not on SecB or FtsY. HflK is
CC       unstable in the absence of HflC.
CC   -!- SIMILARITY: Belongs to the band 7/mec-2 family. HflK subfamily.
CC       {ECO:0000305}.
CC   -!- CAUTION: Was originally (PubMed:2973057) thought to be a protease.
CC       However, removal of residues '165-200' of complex member HflC (a
CC       ClpP-protease-like motif) does not alter the lysogenization
CC       process, and in vitro studies show no evidence of a protease
CC       activity for the isolated HflKC complex.
CC       {ECO:0000305|PubMed:2973057}.
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DR   EMBL; U00005; AAC43399.1; -; Unassigned_DNA.
DR   EMBL; U14003; AAA97070.1; -; Genomic_DNA.
DR   EMBL; U00096; AAC77131.1; -; Genomic_DNA.
DR   EMBL; AP009048; BAE78175.1; -; Genomic_DNA.
DR   PIR; B43653; B43653.
DR   RefSeq; NP_418595.1; NC_000913.3.
DR   RefSeq; WP_000312488.1; NZ_LN832404.1.
DR   ProteinModelPortal; P0ABC7; -.
DR   SMR; P0ABC7; 98-253, 98-286, 128-330, 131-247, 262-313.
DR   BioGrid; 4261253; 425.
DR   DIP; DIP-47481N; -.
DR   IntAct; P0ABC7; 11.
DR   MINT; MINT-1271770; -.
DR   STRING; 511145.b4174; -.
DR   MEROPS; I87.002; -.
DR   EPD; P0ABC7; -.
DR   PaxDb; P0ABC7; -.
DR   PRIDE; P0ABC7; -.
DR   EnsemblBacteria; AAC77131; AAC77131; b4174.
DR   EnsemblBacteria; BAE78175; BAE78175; BAE78175.
DR   GeneID; 948698; -.
DR   KEGG; ecj:JW4132; -.
DR   KEGG; eco:b4174; -.
DR   PATRIC; 32123921; VBIEscCol129921_4305.
DR   EchoBASE; EB0431; -.
DR   EcoGene; EG10436; hflK.
DR   eggNOG; ENOG4107QJR; Bacteria.
DR   eggNOG; COG0330; LUCA.
DR   HOGENOM; HOG000260983; -.
DR   InParanoid; P0ABC7; -.
DR   KO; K04088; -.
DR   OMA; WNEPGGN; -.
DR   PhylomeDB; P0ABC7; -.
DR   BioCyc; EcoCyc:EG10436-MONOMER; -.
DR   BioCyc; ECOL316407:JW4132-MONOMER; -.
DR   BioCyc; MetaCyc:EG10436-MONOMER; -.
DR   PRO; PR:P0ABC7; -.
DR   Proteomes; UP000000318; Chromosome.
DR   Proteomes; UP000000625; Chromosome.
DR   GO; GO:0005829; C:cytosol; IDA:EcoCyc.
DR   GO; GO:0071575; C:integral component of external side of plasma membrane; IDA:EcoCyc.
DR   GO; GO:0009408; P:response to heat; IEP:EcoliWiki.
DR   CDD; cd03404; SPFH_HflK; 1.
DR   InterPro; IPR001107; Band_7.
DR   InterPro; IPR010201; HflK.
DR   InterPro; IPR020980; Membrane_HflK_N.
DR   InterPro; IPR001972; Stomatin_fam.
DR   PANTHER; PTHR10264; PTHR10264; 1.
DR   PANTHER; PTHR10264:SF51; PTHR10264:SF51; 1.
DR   Pfam; PF01145; Band_7; 1.
DR   Pfam; PF12221; HflK_N; 1.
DR   PRINTS; PR00721; STOMATIN.
DR   SMART; SM00244; PHB; 1.
DR   SUPFAM; SSF117892; SSF117892; 1.
DR   TIGRFAMs; TIGR01933; hflK; 1.
PE   1: Evidence at protein level;
KW   Cell inner membrane; Cell membrane; Complete proteome; Membrane;
KW   Reference proteome; Signal-anchor; Transmembrane; Transmembrane helix.
FT   CHAIN         1    419       Modulator of FtsH protease HflK.
FT                                /FTId=PRO_0000094085.
FT   TOPO_DOM      1     79       Cytoplasmic.
FT                                {ECO:0000269|PubMed:9159109}.
FT   TRANSMEM     80    100       Helical; Signal-anchor for type II
FT                                membrane protein. {ECO:0000305}.
FT   TOPO_DOM    101    419       Periplasmic.
FT                                {ECO:0000269|PubMed:9159109}.
FT   MUTAGEN     145    145       A->V: In hflK13; stabilizes overproduced
FT                                SecY but not overproduced cII protein.
FT                                {ECO:0000269|PubMed:8947034}.
SQ   SEQUENCE   419 AA;  45545 MW;  E7B501DC70A49FBC CRC64;
     MAWNQPGNNG QDRDPWGSSK PGGNSEGNGN KGGRDQGPPD LDDIFRKLSK KLGGLGGGKG
     TGSGGGSSSQ GPRPQLGGRV VTIAAAAIVI IWAASGFYTI KEAERGVVTR FGKFSHLVEP
     GLNWKPTFID EVKPVNVEAV RELAASGVML TSDENVVRVE MNVQYRVTNP EKYLYSVTSP
     DDSLRQATDS ALRGVIGKYT MDRILTEGRT VIRSDTQREL EETIRPYDMG ITLLDVNFQA
     ARPPEEVKAA FDDAIAAREN EQQYIREAEA YTNEVQPRAN GQAQRILEEA RAYKAQTILE
     AQGEVARFAK LLPEYKAAPE ITRERLYIET MEKVLGNTRK VLVNDKGGNL MVLPLDQMLK
     GGNAPAAKSD NGASNLLRLP PASSSTTSGA SNTSSTSQGD IMDQRRANAQ RNDYQRQGE
//