Work

Structural Characterization of Four Prochlorosins: A Novel Class of Lantipeptides Produced by Planktonic Marine Cyanobacteria

Year: 2012

Type: article

Abstract: Prochlorosins make up a class of secondary metabolites produced by strains of Prochlorococcus, single-cell, planktonic marine cyanobacteria. These polycyclic peptides contain lanthionine and methyllanthionine residues that result in thioether cross-links. In Prochlorococcus MIT9313, a single enzyme, ProcM, catalyzes the posttranslational modification of 29 linear peptide substrates to generate a library of highly diverse cyclic peptides. To investigate the catalytic promiscuity of ProcM, we chose four prochlorosins previously demonstrated to be produced by the organism for detailed structural characterization. Nuclear magnetic resonance studies allowed unambiguous assignment of the ring topologies, demonstrating a high degree of topological diversity. The stereochemistry of the lanthionine and methyllanthionine residues was determined by gas chromatography and mass spectrometry for seven prochlorosins. All methyllanthionines had the (2S,3S,6R) configuration, and the lanthionines had the (2S,6R) configuration, irrespective of the direction of cyclization, ring size, or ring topology. These findings indicate that most, if not all, of the rings in prochlorosins are formed enzymatically by ProcM lanthionine synthetase and not by a nonenzymatic process as previously suggested.

Source: Biochemistry

DOI: 10.1021/bi300255s

Authors: Weixin Tang, Wilfred A. van der Donk

Institutions: Howard Hughes Medical Institute, University of Illinois Urbana-Champaign

Language: English

Topic: Microbial Natural Products and Biosynthesis

Subfield: Pharmacology (medical)

Field: Medicine

Domain: Health Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: Howard Hughes Medical Institute, National Institutes of Health, National Institute of General Medical Sciences