title: Salmonella Typhimurium methionine sulfoxide reductase A (MsrA) prefers TrxA in repairing methionine sulfoxide.
abstract: Intraphagocytic survival of Salmonella Typhimurium (ST) depends (at least in part) upon its ability to repair oxidant-damaged macromolecules. Met residues either free or in protein bound form are highly susceptible to phagocyte-generated oxidants. Oxidation of Mets leads to Met-SO formation, consequently loss of protein functions that results in cell death. Methionine sulfoxide reductase (Msr) reductively repairs Met-SO to Met in the presence of thioredoxin (trx) and thioredoxin reductase (trxR). Earlier we reported that methionine sulfoxide reductase A (msrA) gene deletion strain of ST suffered oxidative stress.[1]Thioredoxin system of ST comprises of two thioredoxins (trxA and trxC) and one thioredoxin reductase (trxB). Preferred trx utilized in MsrA-mediated repair of Met-SO is not known. In current study, we cloned, expressed, and purified ST TrxA, TrxB, TrxC, and MsrA in recombinant forms. The migration of TrxA, TrxB, TrxC, and MsrA proteins was approximately 10, 36, 16, and 26 kDa on SDS-gels. The nicotinamide adenine dinucleotide phosphate hydrogen (NADPH)-linked reductase assays interpreted that MsrA utilized two times more NADPH for the reduction of S-methyl p-tolyl sulfoxide when TrxA was included in the assays as compared to TrxC.
authors.affiliation: a Division of Immunology , IVRI , UP , India.
authors.forename: Sunil Kumar
authors.initials: SK
authors.lastname: Dixit
authors.affiliation: b Division of Biochemistry , IVRI , UP , India.
authors.forename: Durga Prasad
authors.initials: DP
authors.lastname: Hota
authors.affiliation: b Division of Biochemistry , IVRI , UP , India.
authors.forename: Parvathy
authors.initials: P
authors.lastname: Rajan
authors.affiliation: b Division of Biochemistry , IVRI , UP , India.
authors.forename: Prasanta Kumar K
authors.initials: PK
authors.lastname: Mishra
authors.affiliation: a Division of Immunology , IVRI , UP , India.
authors.forename: Tapas Kumar
authors.initials: TK
authors.lastname: Goswami
authors.affiliation: b Division of Biochemistry , IVRI , UP , India.
authors.forename: Manish
authors.initials: M
authors.lastname: Mahawar
mesh_terms: D003001:Cloning, Molecular; D004587:Electrophoresis, Agar Gel; D008715:Methionine / Q000031:analogs & derivatives* / Q000378:metabolism; D051150:Methionine Sulfoxide Reductases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012486:Salmonella typhimurium / Q000201:enzymology*; D013879:Thioredoxins / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D013879:Thioredoxins; D008715:Methionine; D051150:Methionine Sulfoxide Reductases; C027219:methionine sulfoxide reductase; C013111:methionine sulfoxide
keywords: Methionine sulfoxide reductase A; Salmonella Typhimurium; Thioredoxin