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This Article Full Text Full Text (PDF) Supplementary data All Versions of this Article: mic.0.030643-0v1 155/10/3411    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Google Scholar Articles by Machado, C. X. Articles by Ferreira, H. B. PubMed PubMed Citation Articles by Machado, C. X. Articles by Ferreira, H. B. Agricola Articles by Machado, C. X. Articles by Ferreira, H. B.

A peroxiredoxin from Mycoplasma hyopneumoniae with a possible role in H₂O₂ detoxification

¹ Laboratório de Genômica Estrutural e Funcional, Centro de Biotecnologia, UFRGS, Porto Alegre, RS, Brazil
² Departamento de Biologia Molecular e Biotecnologia, Instituto de Biociências, UFRGS, Porto Alegre-RS, Brazil

Mycoplasma hyopneumoniae is the causative agent of porcine enzootic pneumonia, which affects pig farms worldwide, causing heavy economic losses. In the infection process, this bacterium is exposed to reactive oxygen species (ROS) from its own metabolism or generated by the host as one of the strategies used to neutralize the pathogen. Although the presence of classical antioxidant enzymes would be expected in M. hyopneumoniae, important genes directly related to protection against ROS, such as superoxide dismutase, catalases and glutathione peroxidase, have not been identified by sequence homology in the genome sequence annotation. Among the few identified M. hyopneumoniae genes coding for proteins possibly involved with suppression of ROS-mediated damage, one (tpx) coding for a peroxiredoxin (MhPrx) has been recognized. The sequence and phylogenetic analyses perfomed in this study indicate that MhPrx is closely related to the atypical 2-Cys peroxiredoxin subfamily, although it has only one cysteine in its sequence. The MhPrx coding DNA sequence was cloned and expressed in Escherichia coli to produce a recombinant MhPrx (rMhPrx), which was purified and used to immunize mice and produce an anti-MhPrx polyclonal antiserum. Probing of M. hyopneumoniae extracts with this antiserum demonstrated that MhPrx is expressed in all three tested strains (J, 7422 and 7448). Cross-linking assays and size-exclusion chromatography indicate that rMhPrx forms dimers, as has been established for atypical 2-Cys peroxiredoxins. Furthermore, a metal-catalysed oxidation system was used to assay the activity of rMhPrx, showing that it can protect DNA from ROS-mediated damage and may play an essential role during infection.

Correspondence
Henrique B. Ferreira
henrique{at}cbiot.ufrgs.br

A supplementary table and three supplementary figures are available with the online version of this paper.