title: Functional switching of a novel prokaryotic 2-Cys peroxiredoxin (PpPrx) under oxidative stress.
abstract: Many proteins have been isolated from eukaryotes as redox-sensitive proteins, but whether these proteins are present in prokaryotes is not clear. Redox-sensitive proteins contain disulfide bonds, and their enzymatic activity is modulated by redox in vivo. In the present study, we used thiol affinity purification and mass spectrometry to isolate and identify 19 disulfide-bond-containing proteins in Pseudomonas putida exposed to potential oxidative damages. Among these proteins, we found that a typical 2-Cys Prx-like protein (designated PpPrx) displays diversity in structure and apparent molecular weight (MW) and can act as both a peroxidase and a molecular chaperone. We also identified a regulatory factor involved in this structural and functional switching. Exposure of pseudomonads to hydrogen peroxide (H(2)O(2)) caused the protein structures of PpPrx to convert from high MW complexes to low MW forms, triggering a chaperone-to-peroxidase functional switch. This structural switching was primarily guided by the thioredoxin system. Thus, the peroxidase efficiency of PpPrx is clearly associated with its ability to form distinct protein structures in response to stress.
authors.affiliation: Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongeup, Jeollabuk-do, South Korea.
authors.forename: Byung Chull
authors.initials: BC
authors.lastname: An
authors.forename: Seung Sik
authors.initials: SS
authors.lastname: Lee
authors.forename: Eun Mi
authors.initials: EM
authors.lastname: Lee
authors.forename: Jae Taek
authors.initials: JT
authors.lastname: Lee
authors.forename: Seung Gon
authors.initials: SG
authors.lastname: Wi
authors.forename: Hyun Suk
authors.initials: HS
authors.lastname: Jung
authors.forename: Woojun
authors.initials: W
authors.lastname: Park
authors.forename: Sang Yeol
authors.initials: SY
authors.lastname: Lee
authors.forename: Byung Yeoup
authors.initials: BY
authors.lastname: Chung
mesh_terms: D000595:Amino Acid Sequence; D000975:Antioxidants / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D004220:Disulfides / Q000378:metabolism; D018832:Molecular Chaperones / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D018384:Oxidative Stress; D054464:Peroxiredoxins / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D016958:Pseudomonas putida / Q000201:enzymology*; D011994:Recombinant Proteins / Q000378:metabolism; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D000975:Antioxidants; D001426:Bacterial Proteins; D004220:Disulfides; D018832:Molecular Chaperones; D011994:Recombinant Proteins; D054464:Peroxiredoxins