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 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.
Li
Bo
B
Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Sher
Daniel
D
Kelly
Libusha
L
Shi
Yanxiang
Y
Huang
Katherine
K
Knerr
Patrick J
PJ
Joewono
Ike
I
Rusch
Doug
D
Chisholm
Sallie W
SW
van der Donk
Wilfred A
WA
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
D001426:Bacterial Proteins; D010456:Peptides, Cyclic