Early Steps in the Biosynthetic Pathway of Rishirilide B.

The biological active compound rishirilide B is produced by . The cosmid cos4 contains the complete rishirilide B biosynthesis gene cluster. Its heterologous expression in the host J1074 led to the production of rishirilide B as a major compound and to small amounts of rishirilide A, rishirilide D and lupinacidin A.

Biosynthesis of Rishirilide B.

Rishirilide B was isolated from and on the basis of its inhibitory activity towards alpha-2-macroglobulin. The biosynthesis of rishirilide B was investigated by feeding experiments with different C labelled precursors using the heterologous host J1074::cos4 containing a cosmid encoding of the gene cluster responsible for rishirilide B production. NMR spectroscopic analysis of labelled compounds demonstrate that the tricyclic backbone of rishirilide B is a polyketide synthesized from nine acetate units.

Genome sequence of Streptomyces sp. strain Tü6071.

Streptomyces sp. Tü6071 is a soil-dwelling bacterium which has a highly active isoprenoid biosynthesis. Isoprenoids are important precursors for biopharmaceutical molecules such as antibiotics or anticancer agents, e.