Diversity of Plant Methionine Sulfoxide Reductases B and Evolution of a Form Specific for Free Methionine Sulfoxide

Authors

Dung Tien Le, RIKEN Center for Sustainable Resource ScienceFollow
Lionel Tarrago, Brigham and Women’s Hospital and Harvard Medical School
Yasuko Watanabe, RIKEN Center for Sustainable Resource Science
Alaattin Kaya, Brigham and Women’s Hospital and Harvard Medical School
Byung Cheon Lee, Brigham and Women’s Hospital and Harvard Medical SchoolFollow
Uyen Tran, RIKEN Center for Sustainable Resource Science
Rie Nishiyama, RIKEN Center for Sustainable Resource Science
Dmitri E. Fomenko, University of Nebraska-LincolnFollow
Vadim N. Gladyshev, Harvard Medical SchoolFollow
Lam-Son Phan Tran, RIKEN Center for Sustainable Resource ScienceFollow

Date of this Version

6-2013

Citation

Le DT, Tarrago L, Watanabe Y, Kaya A, Lee BC, et al. (2013) Diversity of Plant Methionine Sulfoxide Reductases B and Evolution of a Form Specific for Free Methionine Sulfoxide. PLoS ONE 8(6): e65637. doi:10.1371/journal.pone.0065637

Comments

Copyright 2013 Le et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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.