ID   MSRQ_CITK8              Reviewed;         206 AA.
AC   A8AQF0;
DT   20-MAY-2008, integrated into UniProtKB/Swiss-Prot.
DT   23-OCT-2007, sequence version 1.
DT   03-AUG-2022, entry version 75.
DE   RecName: Full=Protein-methionine-sulfoxide reductase heme-binding subunit MsrQ {ECO:0000255|HAMAP-Rule:MF_01207};
DE   AltName: Full=Flavocytochrome MsrQ {ECO:0000255|HAMAP-Rule:MF_01207};
GN   Name=msrQ {ECO:0000255|HAMAP-Rule:MF_01207}; OrderedLocusNames=CKO_04663;
OS   Citrobacter koseri (strain ATCC BAA-895 / CDC 4225-83 / SGSC4696).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Enterobacteriaceae; Citrobacter.
OX   NCBI_TaxID=290338;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC BAA-895 / CDC 4225-83 / SGSC4696;
RG   The Citrobacter koseri Genome Sequencing Project;
RA   McClelland M., Sanderson E.K., Porwollik S., Spieth J., Clifton W.S.,
RA   Latreille P., Courtney L., Wang C., Pepin K., Bhonagiri V., Nash W.,
RA   Johnson M., Thiruvilangam P., Wilson R.;
RL   Submitted (AUG-2007) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Part of the MsrPQ system that repairs oxidized periplasmic
CC       proteins containing methionine sulfoxide residues (Met-O), using
CC       respiratory chain electrons. Thus protects these proteins from
CC       oxidative-stress damage caused by reactive species of oxygen and
CC       chlorine generated by the host defense mechanisms. MsrPQ is essential
CC       for the maintenance of envelope integrity under bleach stress, rescuing
CC       a wide series of structurally unrelated periplasmic proteins from
CC       methionine oxidation. MsrQ provides electrons for reduction to the
CC       reductase catalytic subunit MsrP, using the quinone pool of the
CC       respiratory chain. {ECO:0000255|HAMAP-Rule:MF_01207}.
CC   -!- COFACTOR:
CC       Name=FMN; Xref=ChEBI:CHEBI:58210;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01207};
CC       Note=Binds 1 FMN per subunit. {ECO:0000255|HAMAP-Rule:MF_01207};
CC   -!- COFACTOR:
CC       Name=heme b; Xref=ChEBI:CHEBI:60344;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01207};
CC       Note=Binds 1 heme b (iron(II)-protoporphyrin IX) group per subunit.
CC       {ECO:0000255|HAMAP-Rule:MF_01207};
CC   -!- SUBUNIT: Heterodimer of a catalytic subunit (MsrP) and a heme-binding
CC       subunit (MsrQ). {ECO:0000255|HAMAP-Rule:MF_01207}.
CC   -!- SUBCELLULAR LOCATION: Cell inner membrane {ECO:0000255|HAMAP-
CC       Rule:MF_01207}; Multi-pass membrane protein {ECO:0000255|HAMAP-
CC       Rule:MF_01207}.
CC   -!- SIMILARITY: Belongs to the MsrQ family. {ECO:0000255|HAMAP-
CC       Rule:MF_01207}.
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DR   EMBL; CP000822; ABV15713.1; -; Genomic_DNA.
DR   RefSeq; WP_012135388.1; NC_009792.1.
DR   AlphaFoldDB; A8AQF0; -.
DR   SMR; A8AQF0; -.
DR   STRING; 290338.CKO_04663; -.
DR   EnsemblBacteria; ABV15713; ABV15713; CKO_04663.
DR   GeneID; 45138191; -.
DR   KEGG; cko:CKO_04663; -.
DR   HOGENOM; CLU_080662_1_0_6; -.
DR   OMA; LHFFWMR; -.
DR   OrthoDB; 1508607at2; -.
DR   Proteomes; UP000008148; Chromosome.
DR   GO; GO:0005887; C:integral component of plasma membrane; IEA:UniProtKB-UniRule.
DR   GO; GO:0009055; F:electron transfer activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0010181; F:FMN binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0020037; F:heme binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0030091; P:protein repair; IEA:UniProtKB-UniRule.
DR   HAMAP; MF_01207; MsrQ; 1.
DR   InterPro; IPR013130; Fe3_Rdtase_TM_dom.
DR   InterPro; IPR022837; MsrQ-like.
DR   PANTHER; PTHR36964; PTHR36964; 1.
DR   Pfam; PF01794; Ferric_reduct; 1.
PE   3: Inferred from homology;
KW   Cell inner membrane; Cell membrane; Electron transport; Flavoprotein; FMN;
KW   Heme; Iron; Membrane; Metal-binding; Reference proteome; Transmembrane;
KW   Transmembrane helix; Transport.
FT   CHAIN           1..206
FT                   /note="Protein-methionine-sulfoxide reductase heme-binding
FT                   subunit MsrQ"
FT                   /id="PRO_1000085525"
FT   TRANSMEM        8..28
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01207"
FT   TRANSMEM        82..102
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01207"
FT   TRANSMEM        116..136
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01207"
FT   TRANSMEM        153..173
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01207"
SQ   SEQUENCE   206 AA;  23798 MW;  2EE8DFEA55667759 CRC64;
     MRLTQKQIVW LKVLLHLAGL LPFLWLVWAV NQGGLSADPV KDIQHFTGRT ALKFLLATLL
     VSPLARYAKQ PLLIRTRRLL GLWCFAWATL HLTSYALLEL GINNLALLGQ ELITRPYLTL
     GIISWFILFA LTLTSTQAAQ RKLGKRWQRL HNFVYLVAIL APIHYLWSVK ILSPQPVIYA
     LLALVLLAWR YKTFRQWWRS FAGKML