ABSTRACT
The biosynthesis pathways of two anthracyclines, nogalamycin and aclacinomycin, were directed toward angucyclines by using an angucycline-specific cyclase,
pgaF
, isolated from a silent antibiotic biosynthesis gene cluster. Addition of
pgaF
to a gene cassette that harbored the early biosynthesis genes of nogalamycin resulted in the production of two known angucyclinone metabolites, rabelomycin and its precursor, UWM6. Substrate flexibility of
pgaF
was demonstrated by replacement of the nogalamycin minimal polyketide synthase genes in the gene cassette with the equivalent aclacinomycin genes together with
aknE2
and
aknF
, which specify the unusual propionate starter unit in aclacinomycin biosynthesis. This modification led to the production of a novel angucyclinone, MM2002, in which the expected ethyl side chain was incorporated into the fourth ring.
摘要
通过使用血管环素特异性环化酶,将两种蒽环类药物(诺加霉素和阿克拉霉素)的生物合成途径引向血管环素、
pgaF
从一个沉默的抗生素生物合成基因簇中分离出来。加入
pgaF
加入到含有奴加霉素早期生物合成基因的基因盒中,产生了两种已知的安格霉素酮代谢物--雷贝霉素及其前体 UWM6。
pgaF
的底物灵活性是通过将基因盒中的诺加霉素最小多酮合成酶基因替换为等效的阿克拉霉素基因以及
aknE2
和
aknF
这些基因指定了阿克拉霉素生物合成过程中不同寻常的丙酸起始单元。通过这种改造,生产出了一种新型的安格环酮 MM2002,其中第四环中加入了预期的乙基侧链。