Present address: Imperial College of Science, Technology and Medicine, Department of Biology, SAFB, Imperial College Road, SW7 2A2 London, UK.
Identification of new, conserved, non-ribosomal peptide synthetases from fluorescent pseudomonads involved in the biosynthesis of the siderophore pyoverdine
Article first published online: 27 SEP 2002
Volume 45, Issue 6, pages 1673–1685, September 2002
How to Cite
Mossialos, D., Ochsner, U., Baysse, C., Chablain, P., Pirnay, J.-P., Koedam, N., Budzikiewicz, H., Fernández, D. U., Schäfer, M., Ravel, J. and Cornelis, P. (2002), Identification of new, conserved, non-ribosomal peptide synthetases from fluorescent pseudomonads involved in the biosynthesis of the siderophore pyoverdine. Molecular Microbiology, 45: 1673–1685. doi: 10.1046/j.1365-2958.2002.03120.x
- Issue published online: 27 SEP 2002
- Article first published online: 27 SEP 2002
- Accepted 18 June, 2002.
Pyoverdines, the main siderophores of fluorescent pseudomonads, contain a peptide moiety, different for each pyoverdine, and an identical chromophore. While it has been shown that non-ribosomal peptide synthetases (NRPSs) are involved in the biosynthesis of the peptide chain of pyoverdines, this was not demonstrated for the biosynthesis of the chromo-phore part. We found that PvsA, from Pseudomonas fluorescens ATCC 17400, and PvdL (PA2424), from Pseudomonas aeruginosa are similar NRPSs and functional homologues, necessary for the production of pyoverdine. Transcriptional lacZ fusions showed that pvdL is co-transcribed with the upstream PA2425 gene, encoding a putative thioesterase, and is iron-regulated via PvdS. Similarly, RT-PCR analysis revealed that expression of pvsA is repressed by iron. Analysis of the adenylation domains of PvsA, PvdL and their homologues, revealed that their N-terminus starts with an acyl-CoA ligase module, followed by three amino acid activation domains. Computer modelling of these domains suggests that PvsA in P. fluorescens and PvdL in P. aeruginosa are orthologues involved in the biosynthesis of the pyoverdine chromophore.