Catalytic Promiscuity in the Biosynthesis of Cyclic Peptide Secondary Metabolites in Planktonic Marine Cyanobacteria

Our understanding of secondary metabolite production in bacteria has been shaped primarily by studies of attached varieties such as symbionts, pathogens, and soil bacteria. Here we show that a strain of the single-celled, planktonic marine cyanobacterium Prochlorococcus—which conducts a sizable frac...

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Bibliographic Details
Main Authors: Li, Bo, Sher, Daniel, Kelly, Libusha, Shi, Yanxiang, Huang, Katherine H., Knerr, Patrick J., Joewono, Ike, Rusch, Doug, Chisholm, Sallie (Penny), van der Donk, Wilfred A.
Other Authors: Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Format: Article
Language:en_US
Published: National Academy of Sciences (U.S.) 2013
Online Access:http://hdl.handle.net/1721.1/77585
https://orcid.org/0000-0001-6164-5126
Description
Summary:Our understanding of secondary metabolite production in bacteria has been shaped primarily by studies of attached varieties such as symbionts, pathogens, and soil bacteria. Here we show that a strain of the single-celled, planktonic marine cyanobacterium Prochlorococcus—which conducts a sizable fraction of photosynthesis in the oceans—produces many cyclic, lanthionine-containing peptides (lantipeptides). Remarkably, in Prochlorococcus MIT9313 a single promiscuous enzyme transforms up to 29 different linear ribosomally synthesized peptides into a library of polycyclic, conformationally constrained products with highly diverse ring topologies. Genes encoding this system are found in variable abundances across the oceans—with a hot spot in a Galapagos hypersaline lagoon—suggesting they play a habitat- and/or community-specific role. The extraordinarily efficient pathway for generating structural diversity enables these cyanobacteria to produce as many secondary metabolites as model antibiotic-producing bacteria, but with much smaller genomes.