Effects of the deletion and substitution of thioesterase on bacillomycin D synthesis

ObjectivesThe importance of thioesterase domains on bacillomycin D synthesis and the ability of different thioesterase domains to selectively recognize and catalyze peptide chain hydrolysis and cyclization were studied by deleting and substituting thioesterase domains.ResultsNo bacillomycin D analogs were found in the thioesterase-deleted strain fmbJ-Delta TE, indicating that the TE domain was essential for bacillomycin D synthesis. Then the thioesterase in bacillomycin D synthetases was replaced by the thioesterase in bacillomycin F, iturin A, mycosubtilin, plipastatin and surfactin synthetases. Except for fmbJ-S-TE, all others were able to synthesize bacillomycin D homologs because a suitable recombination site was selected, which maintained the integrity of NRPSs. In particular, the yield of bacillomycin D in fmbJ-IA-TE, fmbJ-M-TE and fmbJ-P-TE was significantly increased.ConclusionThis study expands our understanding of the TE domain in bacillomycin D synthetases and shows that thioesterase has excellent potential in the chemical-enzymatic synthesis of natural products or their analogs.

Automated summary

The importance of thioesterase domains in bacillomycin D synthesis and their ability to selectively recognize and catalyze peptide chain hydrolysis and cyclization were studied. Results showed that the TE domain was essential for bacillomycin D synthesis, as no bacillomycin D analogs were found in the strain with the thioesterase domain deleted. By substituting different thioesterase domains, analogs of bacillomycin D were successfully synthesized, with significantly increased yield in certain substitutions.