Journal
JOURNAL OF BACTERIOLOGY
Volume 191, Issue 8, Pages 2551-2560Publisher
AMER SOC MICROBIOLOGY
DOI: 10.1128/JB.01692-08
Keywords
-
Categories
Funding
- Hungarian National Scientific Foundation (OTKA) [K-68053]
- College of Science, Department of Biological Sciences, Rochester Institute of Technology, Rochester, NY
- Merck/AAAS grant
Ask authors/readers for more resources
The stringent response is a mechanism by which bacteria adapt to environmental stresses and nutritional deficiencies through the synthesis and hydrolysis of (p) ppGpp by RelA/SpoT enzymes. Alphaproteobacteria and plants contain a single Rsh enzyme (named for RelA/SpoT homolog) that is bifunctional. Here we report the identification of a new species of bacteria belonging to the genus Novosphingobium and characterization of an rsh mutation in this plant tumor-associated isolate. Isolate Rr 2-17, from a grapevine crown gall tumor, is a member of the Novosphingobium genus that produces the N-acyl-homoserine lactone (AHL) quorum-sensing (QS) signals. A Tn5 mutant, Hx 699, deficient in AHL production was found to have an insertion in an rsh gene. The Rsh protein showed significant percent sequence identity to Rsh proteins of alphaproteobacteria. The Novosphingobium sp. rsh gene (rsh(Nsp)) complemented the multiple amino acid requirements of the Escherichia coli relA spoT double mutant by restoring the growth on selection media. Besides QS signal production, the rsh mutation also affects soluble polysaccharide production and cell aggregation. Genetic complementation of the Hx 699 mutant with the rsh(Nsp) gene restored these phenotypes. This is the first discovery of a functional rsh gene in a member of the Novosphingobium genus.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available