We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
EXPRESSION ANALYSIS AND QUORUM SENSING REGULATION OF GENES INVOLVED IN THE CYCLIC LIPOPEPTIDE CORPEPTIN PRODUCTION IN PSEUDOMONAS CORRUGATA.
- Authors
Strano, C. P.; Bella, P.; Fiore, A.; Licciardello, G.; Fogliano, V.; Venturi, V.; Lo Piero, A. R.; Catara, V.
- Abstract
An ABC (ATP-binding cassette) transport system consisting of two genes and a truncated ORF encoding part of a putative non ribosomal peptide synthetase (NRPS) were identified in a cosmid insert of a genomic library of Pseudomonas corrugata, downstream of the PcoI/PcoR quorum sensing system and the transcriptional regulator rfiA. The genetic organization of this locus shows high similarity with other Pseudomonas cyclic lipopeptide (CLP) biosynthetic clusters. MALDI-TOF MS analysis of cultural filtrates showed that the wild type strain produced two kind of CLPs, cormycin A and corpeptins, whereas derivative mutants of the ABC transport system and NRPS produced only cormycin, thus suggesting that these genes are part of the corpeptin biosynthesis cluster. Moreover, RT-PCR with two set of primers overlapping the three genes demonstrated that they work as an operon. Quantitative real-time RT-PCR showed the presence of NRPS gene transcript in the transporter mutant revealing that corpeptins are still produced via NRPS but not released outside the cell, whereas in the NRPS mutant strain both transporter and synthetase transcripts were undetectable. Time-course analysis of the WT strain revealed that corpeptin NRPS is best expressed at high cell density (108 CFU ml-1), and that the expression could be anticipated by addition of exogenous AHL signals. No expression was detected in the pcoR and rfiA transcriptional regulator mutants. CLPs were undetectable both in the culture filtrates of these mutants and in the WT before the achievement a quorum, suggesting a similar regulation of the cormycin production.
- Subjects
PSEUDOMONAS diseases; BACTERIAL diseases of plants; PEPTIDES; LIGASES; BIOSYNTHESIS
- Publication
Journal of Plant Pathology, 2012, Vol 94, Issue 4, pS4.81
- ISSN
1125-4653
- Publication type
Article