title: Diversity of plant methionine sulfoxide reductases B and evolution of a form specific for free methionine sulfoxide.
abstract: Methionine can be reversibly oxidized to methionine sulfoxide (MetO) under physiological conditions. Organisms evolved two distinct methionine sulfoxide reductase families (MSRA & MSRB) to repair oxidized methionine residues. We found that 5 MSRB genes exist in the soybean genome, including GmMSRB1 and two segmentally duplicated gene pairs (GmMSRB2 and GmMSRB5, GmMSRB3 and GmMSRB4). GmMSRB2 and GmMSRB4 proteins showed MSRB activity toward protein-based MetO with either DTT or thioredoxin (TRX) as reductants, whereas GmMSRB1 was active only with DTT. GmMSRB2 had a typical MSRB mechanism with Cys121 and Cys 68 as catalytic and resolving residues, respectively. Surprisingly, this enzyme also possessed the MSRB activity toward free Met-R-O with kinetic parameters similar to those reported for fRMSR from Escherichia coli, an enzyme specific for free Met-R-O. Overexpression of GmMSRB2 or GmMSRB4 in the yeast cytosol supported the growth of the triple MSRA/MSRB/fRMSR (Δ3MSRs) mutant on MetO and protected cells against H2O2-induced stress. Taken together, our data reveal an unexpected diversity of MSRBs in plants and indicate that, in contrast to mammals that cannot reduce free Met-R-O and microorganisms that use fRMSR for this purpose, plants evolved MSRBs for the reduction of both free and protein-based MetO.
authors.affiliation: Signaling Pathway Research Unit, RIKEN Center for Sustainable Resource Science, Yokohama, Japan. tiendung.le@riken.jp
authors.forename: Dung Tien
authors.initials: DT
authors.lastname: Le
authors.forename: Lionel
authors.initials: L
authors.lastname: Tarrago
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Alaattin
authors.initials: A
authors.lastname: Kaya
authors.forename: Byung Cheon
authors.initials: BC
authors.lastname: Lee
authors.forename: Uyen
authors.initials: U
authors.lastname: Tran
authors.forename: Rie
authors.initials: R
authors.lastname: Nishiyama
authors.forename: Dmitri E
authors.initials: DE
authors.lastname: Fomenko
authors.forename: Vadim N
authors.initials: VN
authors.lastname: Gladyshev
authors.forename: Lam-Son Phan
authors.initials: LS
authors.lastname: Tran
mesh_terms: D001483:Base Sequence; D019295:Computational Biology; D004926:Escherichia coli; D019143:Evolution, Molecular; D017343:Genes, Plant / Q000235:genetics*; D014644:Genetic Variation; D008715:Methionine / Q000031:analogs & derivatives* / Q000378:metabolism; D051150:Methionine Sulfoxide Reductases / Q000235:genetics*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010944:Plants / Q000201:enzymology*; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013025:Glycine max / Q000235:genetics / Q000254:growth & development; D013312:Stress, Physiological / Q000502:physiology; D026801:Synteny / Q000235:genetics; D015003:Yeasts
chemical_list: D008715:Methionine; D051150:Methionine Sulfoxide Reductases; C027219:methionine sulfoxide reductase; C013111:methionine sulfoxide