Feng Xuan, Bello Davide, Lowe Phillip T, Clark Joshua, O'Hagan David
School of Chemistry , University of St Andrews , North Haugh, St Andrews , Fife , KY16 9ST , UK . Email:
Chem Sci. 2019 Aug 20;10(41):9501-9505. doi: 10.1039/c9sc03374b. eCollection 2019 Nov 7.
The antibiotic nucleocidin is a product of the soil bacterium T-3018. It is among the very rare fluorine containing natural products but is distinct from the other fluorometabolites in that it is not biosynthesised from 5'-fluorodeoxyadenosine the fluorinase. It seems to have a unique enzymatic fluorination process. We disclose here the structures of two 4'-fluoro-3'--β-glucosylated metabolites (F-Mets I and II) which appear and then disappear before nucleocidin production in batch cultures of . Full genome sequencing of T-3018 and an analysis of the putative biosynthetic gene cluster for nucleocidin identified UDP-glucose dependent glucosyl transferase () and glucosidase (n) genes within the cluster. We demonstrate that these genes express enzymes that have the capacity to attach and remove glucose from the 3'--position of adenosine analogues. In the case of F-Met II, deglucosylation with the NucGS glucosidase generates nucleocidin suggesting a role in its biosynthesis. Gene knockouts of abolished nucelocidin production.
抗生素核苷菌素是土壤细菌T-3018的产物。它是极为罕见的含氟天然产物之一,但与其他氟代谢产物不同,它不是由5'-氟脱氧腺苷通过氟化酶生物合成的。它似乎具有独特的酶促氟化过程。我们在此披露了两种4'-氟-3'-β-葡萄糖基化代谢产物(F-Mets I和II)的结构,它们在分批培养的T-3018中核苷菌素产生之前出现,然后消失。对T-3018进行全基因组测序并分析核苷菌素的推定生物合成基因簇,发现在该基因簇内有UDP-葡萄糖依赖性葡萄糖基转移酶(NucGT)和葡萄糖苷酶(NucGS)基因。我们证明这些基因表达的酶能够在腺苷类似物的3'-位连接和去除葡萄糖。就F-Met II而言,用NucGS葡萄糖苷酶进行去糖基化产生核苷菌素,表明其在生物合成中起作用。NucGT的基因敲除消除了核苷菌素的产生。