title: Catalytic promiscuity in the biosynthesis of cyclic peptide secondary metabolites in planktonic marine cyanobacteria.
abstract: 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.
authors.affiliation: Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Daniel
authors.initials: D
authors.lastname: Sher
authors.forename: Libusha
authors.initials: L
authors.lastname: Kelly
authors.forename: Yanxiang
authors.initials: Y
authors.lastname: Shi
authors.forename: Katherine
authors.initials: K
authors.lastname: Huang
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Knerr
authors.forename: Ike
authors.initials: I
authors.lastname: Joewono
authors.forename: Doug
authors.initials: D
authors.lastname: Rusch
authors.forename: Sallie W
authors.initials: SW
authors.lastname: Chisholm
authors.forename: Wilfred A
authors.initials: WA
authors.lastname: van der Donk
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055162:Biocatalysis; D017124:Conserved Sequence; D003500:Cyclization; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D005810:Multigene Family; D010456:Peptides, Cyclic / Q000096:biosynthesis*; D010839:Phytoplankton / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D048929:Prochlorococcus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; D010456:Peptides, Cyclic