title: Minimization of the Thiolactomycin Biosynthetic Pathway Reveals that the Cytochrome P450 Enzyme TlmF Is Required for Five-Membered Thiolactone Ring Formation.
abstract: Thiolactomycin (TLM) belongs to a class of rare and unique thiotetronate antibiotics that inhibit bacterial fatty acid synthesis. Although this group of natural product antibiotics was first discovered over 30 years ago, the study of TLM biosynthesis remains in its infancy. We recently discovered the biosynthetic gene cluster (BGC) for TLM from the marine bacterium Salinispora pacifica CNS-863. Here, we report the investigation of TLM biosynthetic logic through mutagenesis and comparative metabolic analyses. Our results revealed that only four genes (tlmF, tlmG, tlmH, and tlmI) are required for the construction of the characteristic γ-thiolactone skeleton of this class of antibiotics. We further showed that the cytochrome P450 TlmF does not directly participate in sulfur insertion and C-S bond formation chemistry but rather in the construction of the five-membered thiolactone ring as, upon its deletion, we observed the alternative production of the six-membered δ-thiolactomycin. Our findings pave the way for future biochemical investigation of the biosynthesis of this structurally unique group of thiotetronic acid natural products.
authors.affiliation: Center of Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0204, USA.
authors.forename: Xiaoyu
authors.identifier: 0000-0002-7855-5984
authors.initials: X
authors.lastname: Tang
authors.affiliation: Center of Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0204, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.affiliation: Center of Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0204, USA.|Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
authors.forename: Bradley S
authors.identifier: 0000-0002-4652-1253
authors.initials: BS
authors.lastname: Moore
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000737:chemistry; D059001:Aquatic Organisms; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000235:genetics; D003001:Cloning, Molecular; D003500:Cyclization; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005818:Genetic Engineering; D008848:Micromonosporaceae / Q000201:enzymology / Q000235:genetics*; D005810:Multigene Family; D016296:Mutagenesis; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D013237:Stereoisomerism; D048372:Streptomyces coelicolor / Q000235:genetics / Q000378:metabolism; D013876:Thiophenes / Q000737:chemistry / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D013876:Thiophenes; C035068:thiolactomycin; D003577:Cytochrome P-450 Enzyme System
keywords: Salinispora; biosynthesis; fatty acid synthase inhibitor; thiolactone ring; thiotetronate antibiotics