ID   MERA_STAAU              Reviewed;         547 AA.
AC   P0A0E5; P08663;
DT   01-JAN-1988, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1988, sequence version 1.
DT   03-AUG-2022, entry version 89.
DE   RecName: Full=Mercuric reductase;
DE            EC=1.16.1.1;
DE   AltName: Full=Hg(II) reductase;
GN   Name=merA;
OS   Staphylococcus aureus.
OG   Plasmid pI258.
OC   Bacteria; Firmicutes; Bacilli; Bacillales; Staphylococcaceae;
OC   Staphylococcus.
OX   NCBI_TaxID=1280;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=3037534; DOI=10.1073/pnas.84.15.5106;
RA   Laddaga R.A., Chu L., Misra T.K., Silver S.;
RT   "Nucleotide sequence and expression of the mercurial-resistance operon from
RT   Staphylococcus aureus plasmid pI258.";
RL   Proc. Natl. Acad. Sci. U.S.A. 84:5106-5110(1987).
CC   -!- FUNCTION: Resistance to Hg(2+) in bacteria appears to be governed by a
CC       specialized system which includes mercuric reductase. MerA protein is
CC       responsible for volatilizing mercury as Hg(0) (By similarity).
CC       {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=H(+) + Hg + NADP(+) = Hg(2+) + NADPH; Xref=Rhea:RHEA:23856,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:16170, ChEBI:CHEBI:16793,
CC         ChEBI:CHEBI:57783, ChEBI:CHEBI:58349; EC=1.16.1.1;
CC   -!- COFACTOR:
CC       Name=FAD; Xref=ChEBI:CHEBI:57692; Evidence={ECO:0000250};
CC       Note=Binds 1 FAD per subunit. {ECO:0000250};
CC   -!- SUBUNIT: Homodimer. {ECO:0000250}.
CC   -!- MISCELLANEOUS: The active site is a redox-active disulfide bond.
CC       {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the class-I pyridine nucleotide-disulfide
CC       oxidoreductase family. {ECO:0000305}.
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DR   EMBL; L29436; AAA98245.1; -; Genomic_DNA.
DR   PIR; E29504; E29504.
DR   RefSeq; WP_000193219.1; NZ_WBTO01000038.1.
DR   RefSeq; YP_006937593.1; NC_013319.1.
DR   RefSeq; YP_006938295.1; NC_013337.1.
DR   RefSeq; YP_006938628.1; NC_013347.1.
DR   RefSeq; YP_006938790.1; NC_013352.1.
DR   RefSeq; YP_006958467.1; NC_018968.1.
DR   AlphaFoldDB; P0A0E5; -.
DR   SMR; P0A0E5; -.
DR   OMA; GGATQRM; -.
DR   GO; GO:0050660; F:flavin adenine dinucleotide binding; IEA:InterPro.
DR   GO; GO:0016152; F:mercury (II) reductase activity; IEA:UniProtKB-EC.
DR   GO; GO:0045340; F:mercury ion binding; IEA:InterPro.
DR   GO; GO:0050661; F:NADP binding; IEA:InterPro.
DR   GO; GO:0016668; F:oxidoreductase activity, acting on a sulfur group of donors, NAD(P) as acceptor; IEA:InterPro.
DR   GO; GO:0045454; P:cell redox homeostasis; IEA:InterPro.
DR   GO; GO:0050787; P:detoxification of mercury ion; IEA:InterPro.
DR   CDD; cd00371; HMA; 1.
DR   Gene3D; 3.30.390.30; -; 1.
DR   Gene3D; 3.50.50.60; -; 2.
DR   InterPro; IPR036188; FAD/NAD-bd_sf.
DR   InterPro; IPR023753; FAD/NAD-binding_dom.
DR   InterPro; IPR016156; FAD/NAD-linked_Rdtase_dimer_sf.
DR   InterPro; IPR017969; Heavy-metal-associated_CS.
DR   InterPro; IPR006121; HMA_dom.
DR   InterPro; IPR036163; HMA_dom_sf.
DR   InterPro; IPR021179; Mercury_reductase_MerA.
DR   InterPro; IPR001100; Pyr_nuc-diS_OxRdtase.
DR   InterPro; IPR004099; Pyr_nucl-diS_OxRdtase_dimer.
DR   InterPro; IPR012999; Pyr_OxRdtase_I_AS.
DR   Pfam; PF00403; HMA; 1.
DR   Pfam; PF07992; Pyr_redox_2; 1.
DR   Pfam; PF02852; Pyr_redox_dim; 1.
DR   PIRSF; PIRSF000350; Mercury_reductase_MerA; 1.
DR   SUPFAM; SSF51905; SSF51905; 1.
DR   SUPFAM; SSF55008; SSF55008; 1.
DR   SUPFAM; SSF55424; SSF55424; 1.
DR   TIGRFAMs; TIGR02053; MerA; 1.
DR   PROSITE; PS01047; HMA_1; 1.
DR   PROSITE; PS50846; HMA_2; 1.
DR   PROSITE; PS00076; PYRIDINE_REDOX_1; 1.
PE   3: Inferred from homology;
KW   Disulfide bond; FAD; Flavoprotein; Mercuric resistance; Mercury;
KW   Metal-binding; NADP; Oxidoreductase; Plasmid; Redox-active center.
FT   CHAIN           1..547
FT                   /note="Mercuric reductase"
FT                   /id="PRO_0000068002"
FT   DOMAIN          4..67
FT                   /note="HMA"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00280"
FT   BINDING         15
FT                   /ligand="a metal cation"
FT                   /ligand_id="ChEBI:CHEBI:25213"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00280"
FT   BINDING         18
FT                   /ligand="a metal cation"
FT                   /ligand_id="ChEBI:CHEBI:25213"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00280"
FT   BINDING         115..123
FT                   /ligand="FAD"
FT                   /ligand_id="ChEBI:CHEBI:57692"
FT                   /evidence="ECO:0000250"
FT   BINDING         544
FT                   /ligand="Hg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:16793"
FT   BINDING         545
FT                   /ligand="Hg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:16793"
FT   DISULFID        123..128
FT                   /note="Redox-active"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   547 AA;  58566 MW;  B0BEA5FCFA99C049 CRC64;
     MTQNSYKIPI QGMTCTGCEE HVTEALEQAG AKDVSADFRR GEAIFELSDD QIEKAKQNIS
     AAGYQPGEEE SQPSENSVDF NRDGDYDLLI IGSGGAAFSA AIKANENGAK VAMVERGTVG
     GTCVNIGCVP SKTMLRAGEI NGLAQNNPFT GLQTSTGAAD LAQLTEQKDG LVSQMRQEKY
     IDLIEEYGFD LIRGEASFID DKTIQVNGQN ITSKSFLIAT GASPAVPEIP GMNEVDYLTS
     TSALELKEVP QRLAVIGSGY IAAELGQMFH NLGTEVTLMQ RSERLFKTYD PEISEAIDES
     LTEQGLNLIT GVTYQKVEQN GKSTSIYIEV NGQEQVIEAD QVLVATGRKP NTETLNLESA
     GVKTGKKGEV LTNEYLQTSN NRIYAAGDVT LGPQFVYVAA YEGGIVANNA LGLAKRKIDL
     RFVPGVTFTN PSIATVGLTE QQAKEKGYDV KTSVLPLDAV PRALVNHETT GVYKLVVNAQ
     TQKLIGAHIV SENAGDVIYA ATLAVQFGLT IEDLTDSFAP YLTMAEGLKL AALTFDKDVS
     KLSCCAG