Structure and function of CinD (YtjD) of Lactococcus lactis, a copper-induced nitroreductase involved in defense against oxidative stress
Publisher DOI
PubMed ID
20562311
Abstract
In Lactococcus lactis IL1403, 14 genes are under the control of the copper-inducible CopR repressor. This so-called CopR regulon encompasses the CopR regulator, two putative CPx-type copper ATPases, a copper chaperone, and 10 additional genes of unknown function. We addressed here the function of one of these genes, ytjD, which we renamed cinD (copper-induced nitroreductase). Copper, cadmium, and silver induced cinD in vivo, as shown by real-time quantitative PCR. A knockout mutant of cinD was more sensitive to oxidative stress exerted by 4-nitroquinoline-N-oxide and copper. Purified CinD is a flavoprotein and reduced 2,6-dichlorophenolindophenol and 4-nitroquinoline-N-oxide with k(cat) values of 27 and 11 s(-1), respectively, using NADH as a reductant. CinD also exhibited significant catalase activity in vitro. The X-ray structure of CinD was resolved at 1.35 A and resembles those of other nitroreductases. CinD is thus a nitroreductase which can protect L. lactis against oxidative stress that could be exerted by nitroaromatic compounds and copper.
Date Issued
2010
Publication Type
Article
Language(s)
en
Author(s)
Mermod, Mélanie | |
Mourlane, Frédéric | |
Waltersperger, Sandro | |
Oberholzer, Anselm E | |
Baumann, Ulrich |
Additional Credits
Journal
Journal of bacteriology
Publisher
American Society for Microbiology
ISSN
0021-9193
Access(Rights)
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