The Analysis of the Glycosyltransferase Gene Function From a Novel Granaticin Producer, Streptomyces Vilmorinianum. YP1.

Glycosylation is common among the synthesis of natural product and imparts the bioactivity for natural product. As for granaticin, a natural product with great bioactivity, glycosylation is an unusual sugar attachment and remains enigmatic. Orf14 in the gra cluster is the predicted glycosyltransferase but without being identified. Recently, we isolated and identified a novel granaticin producer Streptomyces vilmorinianum YP1. Orf14 gene in gra cluster of YP1 is knocked out and complemented. The instrumental analysis of the blue product synthesized by orf14-deficient mutant exhibits the none-granaticin detection and deglycosylated intermediates accumulation. The bioactivity and stability test suggests the weaker or none antibacterial activity and cytotoxicity of this blue product with greater ultraviolet stability and thermostability than granaticin and derivatives produced by YP1. All the result indicates that orf14 encodes glycosyltransferase and glycosylation played an important role in the bioactivity of granaticin. Meanwhile, the blue pigment, deglycosylated intermediates, has favorable processing characteristics. Our finding supplies the function of orf14 and glycosylation, but also indicates a promising candidate of edible blue pigment applicated in food industry.