7SFN

Crystal structure of OlmO, a spirocyclase involved in the biosynthesis of oligomycin

Summary for 7SFN

• Entry DOI: 10.2210/pdb7sfn/pdb
• Descriptor: OlmO - oligomycin spirocyclase, D-MALATE (3 entities in total)
• Functional Keywords: cyclase, spyrocyclase, oligomycin, calycin, hydrolase
• Biological source: Streptomyces avermitilis
• Total number of polymer chains: 2
• Total formula weight: 43255.22

Authors

Bilyk, O.,Leadlay, P.F.,Dias, M.V.B. (deposition date: 2021-10-04, release date: 2022-08-17, Last modification date: 2024-05-22)

Primary citation

Bilyk, O.,Oliveira, G.S.,de Angelo, R.M.,Almeida, M.O.,Honorio, K.M.,Leeper, F.J.,Dias, M.V.B.,Leadlay, P.F.
Enzyme-Catalyzed Spiroacetal Formation in Polyketide Antibiotic Biosynthesis.
J.Am.Chem.Soc., 144:14555-14563, 2022

PubMed Abstract: A key step in the biosynthesis of numerous polyketides is the stereospecific formation of a spiroacetal (spiroketal). We report here that spiroacetal formation in the biosynthesis of the macrocyclic polyketides ossamycin and oligomycin involves catalysis by a novel spiroacetal cyclase. OssO from the ossamycin biosynthetic gene cluster (BGC) is homologous to OlmO, the product of an unannotated gene from the oligomycin BGC. The deletion of abolished oligomycin production and led to the isolation of oligomycin-like metabolites lacking the spiroacetal structure. Purified OlmO catalyzed complete conversion of the major metabolite into oligomycin C. Crystal structures of OssO and OlmO reveal an unusual 10-strand β-barrel. Three conserved polar residues are clustered together in the β-barrel cavity, and site-specific mutation of any of these residues either abolished or substantially diminished OlmO activity, supporting a role for general acid/general base catalysis in spiroacetal formation.

PubMed: 35921248
DOI: 10.1021/jacs.2c03313

Experimental method

X-RAY DIFFRACTION (2.1 Å)