Ohr (Organic Hydroperoxide Resistance Protein) Possesses a Previously Undescribed Activity, Lipoyl-dependent Peroxidase

Autor(es)

Cussiol, Jose R. R. ^[1] ; Alegria, Thiago G. P. ^[1] ; Szweda, Luke I. ^[2] ; Netto, Luis E. S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biociencias, Dept Genet & Biol Evolut, BR-05508900 Sao Paulo - Brazil

^[2] Oklahoma Med Res Fdn, Free Rad Biol & Aging Res Program, Oklahoma City, OK 73104 - USA

• Tipo de documento: Artigo Científico
• Fonte: Journal of Biological Chemistry; v. 285, n. 29, p. 21943-21950, JUL 16 2010.
• Citações Web of Science: 35

Resumo

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. (AU)

• Processo FAPESP: 07/58147-6 - Aspectos biológicos de tióis: estrutura protéica, defesa antioxidante, sinalização e estados redox
• Beneficiário: Luis Eduardo Soares Netto
• Modalidade de apoio: Auxílio à Pesquisa - Temático