Structure of fuscopeptins, phytotoxic metabolites of Pseudomonas fuscovaginae

Abstract

The structure of the fuscopeptins, bioactive lipodepsipeptides produced in culture by the gramineae pathogen Pseudomonas fuscovaginae, has been determined. The combined use of FAB mass spectrometry, NMR spectroscopy and chemical and enzymatic procedures allowed one to define a peptide moiety corresponding to ZDhb-DPro-LLeu-DAIa-DAIa-DAla-DAIaDVai-Gly-DAIa-DVaI-DAIa-DVaI-ZDhb-DaThr-LAIa-LDabDDab-LPbe with the terminal carboxyl group closing a macrocyclic ring on the hydroxyl group of the allothreonine residue. The N-terminus is in turn acylated by 3-hydroxyoctanoate in fuscopeptin A and 3-hydroxydecanoate in fuscopeptin B. Some preliminary data on the biological activity of fuscopeptins are also reported.

Corceptins, new bioactive lipodepsipeptides from cultures of Pseudomonas corrugata

“…1) showed two major peaks in the region where SPs and FPs, respectively from P. syringae pv. syringae [10] and P. fuscovaginae [14], are eluted. Prominent peaks in the region of lipodepsinonapeptides were not observed.…”

“…Amino acid analyses of acid hydrolyzed CPs, GC-MS analyses of their TBDMS derivatives, automated Edman degradations of peptides, and FAB-MS spectra were carried out as reported in [14]. The J H-NMR spectra of samples (approximately 0.8 mg/ml) were run at 27°C on a Bruker AMX600 instrument operating at 600.14 MHz.…”

“…These belong to two groups, one formed by nonapeptides that share many structural features (syringomycins [1 3], syringotoxins [4][5][6], syringostatins [7,8], pseudomycins [9]), the other by lipodepsipeptides with a longer and more hydrophobic peptide moiety (syringopeptins [10][11][12][13], fuscopeptins [14], tolaasins [15]). Both types occurs at the same time in cultures of several ecotypes of Pseudomonas s'yringae pv.…”

“…syringae [10 13], of P. syringae pv. atrofaciens [16], of saprophytic P. syringae [17], of a transposon generated regulatory mutant of a P. s'yringae strain (pathovar not assigned) [9] and of P. fi~scovaginae [14].…”

Draft Genome Sequence of Pseudomonas fuscovaginae, a Broad-Host-Range Pathogen of Plants

“…A total of 3 rRNA and 48 tRNA genes were also identified in the RAST annotation. P. fuscovaginae produces three different types of phytotoxic metabolites, syringotoxin, fuscopeptin A (FP-A), and fuscopeptin B (FP-B), that have been shown to be involved in generating the disease symptoms (3,7). Despite the importance of P. fuscovaginae as a plant pathogen on several plant hosts around the world, very few studies of the virulence and biology of this pathogen have been performed.…”