1887

Abstract

Sequencing of the strain 1021 genome led to the detection of 6204 open reading frames, 41 % of which have no hypothetical function. To help annotate this genome, a transcriptome analysis was carried out with a dedicated microarray consisting of 146 genes belonging to three different classes: (i) no hypothetical function; (ii) potentially involved in oxidative stress responses; (iii) known to participate in oxidative stress responses (e.g. catalase and superoxide dismutase genes). This transcriptome analysis, together with biological experiments and investigations, identified new genes induced by exogenous HO. The gene was the most strongly induced: quantitative PCR showed that the amount of mRNA increased 50-fold following the addition of 10 mM HO, whereas the amount of mRNA (encoding a catalase) only increased 10-fold. Smc01944 is a non-haem chloroperoxidase (Cpo). The only member of this family to have been so far characterized is encoded by of . Unexpectedly, the NH-terminus of Smc01944 includes a signal peptide and Smc01944 is secreted into the supernatant. Interestingly, is preceded by , encoding an OhrR-like regulator (MarR family). Thus, Smc01944 is the first exported Cpo encoded by a gene possibly regulated by an OhrR regulator. It was also shown that is induced by t-butyl and cumene hydroperoxides but only slightly by menadione. The study of Smc01944 described in this work showed that the oxidative stress response of seems to differ from that of other bacteria characterized to date.

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2004-03-01
2019-11-14
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