MERA_ACICA
ID MERA_ACICA Reviewed; 561 AA.
AC Q52109;
DT 01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1996, sequence version 1.
DT 03-AUG-2022, entry version 119.
DE RecName: Full=Mercuric reductase;
DE EC=1.16.1.1;
DE AltName: Full=Hg(II) reductase;
GN Name=merA;
OS Acinetobacter calcoaceticus.
OG Plasmid pKLH2.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Moraxellales; Moraxellaceae;
OC Acinetobacter; Acinetobacter calcoaceticus/baumannii complex.
OX NCBI_TaxID=471;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=8302940; DOI=10.1006/plas.1993.1064;
RA Kholodii G.Y., Lomovskaya O.L., Gorlenko Z.M., Mindlin S.Z., Yurieva O.V.,
RA Nikiforov V.G.;
RT "Molecular characterization of an aberrant mercury resistance transposable
RT element from an environmental Acinetobacter strain.";
RL Plasmid 30:303-308(1993).
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).
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 -!- SIMILARITY: Belongs to the class-I pyridine nucleotide-disulfide
CC oxidoreductase family. {ECO:0000305}.
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DR EMBL; AF213017; AAA19682.1; -; Genomic_DNA.
DR RefSeq; WP_004644736.1; NZ_MOSW01000200.1.
DR AlphaFoldDB; Q52109; -.
DR SMR; Q52109; -.
DR GeneID; 66271196; -.
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..561
FT /note="Mercuric reductase"
FT /id="PRO_0000067993"
FT DOMAIN 1..65
FT /note="HMA"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00280"
FT BINDING 11
FT /ligand="a metal cation"
FT /ligand_id="ChEBI:CHEBI:25213"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00280"
FT BINDING 14
FT /ligand="a metal cation"
FT /ligand_id="ChEBI:CHEBI:25213"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00280"
FT BINDING 128..136
FT /ligand="FAD"
FT /ligand_id="ChEBI:CHEBI:57692"
FT /evidence="ECO:0000250"
FT BINDING 558
FT /ligand="Hg(2+)"
FT /ligand_id="ChEBI:CHEBI:16793"
FT BINDING 559
FT /ligand="Hg(2+)"
FT /ligand_id="ChEBI:CHEBI:16793"
FT DISULFID 136..141
FT /note="Redox-active"
FT /evidence="ECO:0000250"
SQ SEQUENCE 561 AA; 58559 MW; 111E02A702C157D6 CRC64;
MTTLKITGMT CDSCAAHVKE ALEKVPGVQS ALVSYPKGTA QLAIEAGTSS DALTTAVAGL
GYEATLADAP PTDNRAGLLD KMRGWIGAAD KPSGNERPLQ VVVIGSGGAA MAAALKAVEQ
GAHVSLIERG TIGGTCVNVG CVPSKIMIRA AHIAHLRRES PFDGGIAATV PAIDRSKLLA
QQQARVEELR HAKYEGILDG NPAITVVHGE ARFKDEQSLV VRLNDGGERV VAFDRCLVAT
GASPAVPPIP GLKESPYWTS TEALVSDTLP ERLAVIGSSV VALELAQAFA RLGSQVTILA
RNTLFFRDDP AIGEAVTAAF RAEGIKVLEH TQASQVAHVD GEFVLTTGYG EIRADQLLVA
TGRAPNTRSL ALEAAGVAAN AQGAIVIDKG MRTSTPHIYA AGDCTDQPQF VYVAAAAGTR
AAINMTGGDA ALDLTAMPAV VFTDPQVATV GYSEAEAHHD GIETDSRTLT LDNVPRALAN
FDTRGFIKLV IEEGSGRLIG VQAVAPEAGE LIQTAVLAIR NRMTVQELAD QLFPYLTMVE
GLKLAAQTFS KDVKQLSCCA G
