title: Massetolide A biosynthesis in Pseudomonas fluorescens.
abstract: Massetolide A is a cyclic lipopeptide (CLP) antibiotic produced by various Pseudomonas strains from diverse environments. Cloning, sequencing, site-directed mutagenesis, and complementation showed that massetolide A biosynthesis in P. fluorescens SS101 is governed by three nonribosomal peptide synthetase (NRPS) genes, designated massA, massB, and massC, spanning approximately 30 kb. Prediction of the nature and configuration of the amino acids by in silico analysis of adenylation and condensation domains of the NRPSs was consistent with the chemically determined structure of the peptide moiety of massetolide A. Structural analysis of massetolide A derivatives produced by SS101 indicated that most of the variations in the peptide moiety occur at amino acid positions 4 and 9. Regions flanking the mass genes contained several genes found in other Pseudomonas CLP biosynthesis clusters, which encode LuxR-type transcriptional regulators, ABC transporters, and an RND-like outer membrane protein. In contrast to most Pseudomonas CLP gene clusters known to date, the mass genes are not physically linked but are organized in two separate clusters, with massA disconnected from massB and massC. Quantitative real-time PCR analysis indicated that transcription of massC is strongly reduced when massB is mutated, suggesting that these two genes function in an operon, whereas transcription of massA is independent of massBC and vice versa. Massetolide A is produced in the early exponential growth phase, and biosynthesis appears not to be regulated by N-acylhomoserine lactone-based quorum sensing. Massetolide A production is essential in swarming motility of P. fluorescens SS101 and plays an important role in biofilm formation.
authors.affiliation: Laboratory of Phytopathology, Wageningen University, The Netherlands.
authors.forename: I
authors.initials: I
authors.lastname: de Bruijn
authors.forename: M J D
authors.initials: MJ
authors.lastname: de Kock
authors.forename: P
authors.initials: P
authors.lastname: de Waard
authors.forename: T A
authors.initials: TA
authors.lastname: van Beek
authors.forename: J M
authors.initials: JM
authors.lastname: Raaijmakers
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000737:chemistry; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D008124:Locomotion; D005810:Multigene Family; D016254:Mutagenesis, Insertional; D009876:Operon; D010453:Peptide Synthases / Q000235:genetics* / Q000378:metabolism; D010456:Peptides, Cyclic / Q000096:biosynthesis* / Q000737:chemistry; D011551:Pseudomonas fluorescens / Q000235:genetics / Q000502:physiology*; D012329:RNA, Bacterial / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D010456:Peptides, Cyclic; D012329:RNA, Bacterial; D012333:RNA, Messenger; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase