TY - JOUR
T1 - Ohr (organic hydroperoxide resistance protein) possesses a previously undescribed activity, lipoyl-dependent peroxidase
AU - Cussiol, J. R R
AU - Alegria, T. G P
AU - Szweda, Luke I.
AU - Netto, L. E S
PY - 2010/7/16
Y1 - 2010/7/16
N2 - The Ohr (organic hydroperoxide resistance) family of 15-kDa Cys-based, thiol-dependent peroxidases is central to the bacterial response to stress induced by organic hydroperoxides but not by hydrogen peroxide. Ohr has a unique three-dimensional structure and requires dithiols, but not monothiols, to support its activity. However, the physiological reducing system of Ohr has not yet been identified. Here we show that lipoylated enzymes present in the bacterial extracts of Xylella fastidiosa interacted physically and functionally with this Cys-based peroxidase, whereas thioredoxin and glutathione systems failed to support Ohr peroxidase activity. Furthermore, we could reconstitute in vitro three lipoyl-dependent systems as the Ohr physiological reducing systems. We also showed that OsmC from Escherichia coli, an orthologue of Ohr from Xylella fastidiosa, is specifically reduced by lipoyl-dependent systems. These results represent the first description of a Cys-based peroxidase that is directly reduced by lipoylated enzymes.
AB - The Ohr (organic hydroperoxide resistance) family of 15-kDa Cys-based, thiol-dependent peroxidases is central to the bacterial response to stress induced by organic hydroperoxides but not by hydrogen peroxide. Ohr has a unique three-dimensional structure and requires dithiols, but not monothiols, to support its activity. However, the physiological reducing system of Ohr has not yet been identified. Here we show that lipoylated enzymes present in the bacterial extracts of Xylella fastidiosa interacted physically and functionally with this Cys-based peroxidase, whereas thioredoxin and glutathione systems failed to support Ohr peroxidase activity. Furthermore, we could reconstitute in vitro three lipoyl-dependent systems as the Ohr physiological reducing systems. We also showed that OsmC from Escherichia coli, an orthologue of Ohr from Xylella fastidiosa, is specifically reduced by lipoyl-dependent systems. These results represent the first description of a Cys-based peroxidase that is directly reduced by lipoylated enzymes.
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U2 - 10.1074/jbc.M110.117283
DO - 10.1074/jbc.M110.117283
M3 - Article
C2 - 20463026
AN - SCOPUS:77954590069
SN - 0021-9258
VL - 285
SP - 21943
EP - 21950
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 29
ER -