期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2017
卷号：114
期号：16
页码：4135-4140
DOI：10.1073/pnas.1701361114
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The protein synthesis inhibitor anisomycin features a unique benzylpyrrolidine system and exhibits diverse biological and pharmacologic activities. Its biosynthetic origin has remained obscure for more than 60 y, however. Here we report the identification of the biosynthetic gene cluster (BGC) of anisomycin in Streptomyces hygrospinosus var. beijingensis by a bioactivity-guided high-throughput screening method. Using a combination of bioinformatic analysis, reverse genetics, chemical analysis, and in vitro biochemical assays, we have identified a core four-gene ensemble responsible for the synthesis of the pyrrolidine system in anisomycin: aniQ , encoding a aminotransferase that catalyzes an initial deamination and a later reamination steps; aniP , encoding a transketolase implicated to bring together an glycolysis intermediate with 4-hydroxyphenylpyruvic acid to form the anisomycin molecular backbone; aniO , encoding a glycosyltransferase that catalyzes a cryptic glycosylation crucial for downstream enzyme processing; and aniN , encoding a bifunctional dehydrogenase that mediates multistep pyrrolidine formation. The results reveal a BGC for pyrrolidine alkaloid biosynthesis that is distinct from known bacterial alkaloid pathways, and provide the signature sequences that will facilitate the discovery of BGCs encoding novel pyrrolidine alkaloids in bacterial genomes. The biosynthetic insights from this study further set the foundation for biosynthetic engineering of pyrrolidine antibiotics.
