Functional analysis of a gene cluster for putative bacteriocin deduced from the genome sequence of Aeribacillus pallidus PI8

[摘要] Bacteriocins are a large family of peptides synthesized ribosomally by a variety of bacterial species.The genome of one of the thermophilic Gram-positivebacteria, Aeribacillus pallidus PI8, was found topossess an operon comprising five genes possiblyinvolved in the production of a putative bacteriocinthat was named pcnABCDE for the production of“pallidocyclicin.” This study investigated the function of the pcn operon experimentally. The heterologous expression of the entire pcn operon from theplasmid was toxic to Escherichia coli but not toBacillus subtilis. However, when the entire pcnoperon was expressed constitutively, even the growthof B. subtilis was impaired, and at least pcnA wasimplied to serve as the precursor of pallidocyclicin.In addition, a strain of B. subtilis expressing theentire pcn operon from the plasmid showed toxicityto another thermophilic species, Geobacilluskaustophilus, at elevated temperatures, whereasanother strain lacking pcnE alone from the pcnoperon lost the toxicity, suggesting that pcnE mightbe involved in the biosynthesis of pallidocyclicinwhen it is produced in B. subtilis.

[学科分类] 微生物学和免疫学

[关键词] Aeribacillus pallidus;bacteriocin;Geobacillus;Gram-positive;thermophile