This Article Full Text (PDF) Other Versions of this Article: JB.00377-07v1 189/14/5361    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Quaranta, D. Articles by Rensing, C. Search for Related Content PubMed PubMed Citation Articles by Quaranta, D. Articles by Rensing, C.

 Previous Article  |  Next Article 

J. Bacteriol. doi:10.1128/JB.00377-07
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

The copper-inducible cin operon encodes an unusual methionine-rich azurin like protein and a preQ₀ reductase in Pseudomonas putida KT2440

Department of Soil, Water, and Environmental Science; Department of Biochemistry and Molecular Biophysics, University of Arizona, Tucson, AZ 85721

^* To whom correspondence should be addressed. Email: rensingc{at}ag.arizona.edu.

	Abstract

The genome sequence of several pseudomonads have revealed a gene cluster containing a two component heavy metal histidine sensor kinase and response regulator upstream of cinA and cinQ, which we show herein to encode a copper containing azurin-like protein and a preQ_o reductase, respectively. In the presence of copper, Pseudomonas putida KT2440 produces the CinA and CinQ proteins from a bicistronic mRNA. UV-visible spectra of CinA show features at 439, 581 and 719 nm, which are typical of plastocyanin family of proteins. The redox potential of the protein was shown to be 456 ± 4 mV by voltametric titrations. Surprisingly, CinQ is a pyridine nucleotide-dependent nitrile oxidoreductase that catalyzes the conversion of preQ₀ to preQ₁, in the nucleoside queuosine biosynthetic pathway. Gene disruptions of cinA and cinQ did not lead to a significant increase in copper sensitivity in P. putida KT2440 under the conditions tested. Possible roles of CinA and CinQ to help pseudomonads adapt and survive under prolonged copper stress are discussed.