TARGETED SCREENING FOR ELONGATION-FACTOR TU BINDING ANTIBIOTICS

The development of a screen targeted to antibiotics which bind elongat ion factor Tu (EF-Tu) is described. The method was based on selection of antimicrobial activities which were antagonized by exogenous EF-Tu. Kirromycin, a known inhibitor of EF-Tu, was positive in this screen. Among 47,000 microorganisms screened, several producers of kirromycin- type antibiotics were detected and the novel antibiotics GE2270 and GE 37468 were discovered. These thiopeptide molecules constitute, along w ith amithiamycin, a novel class of antibiotics acting on EF-Tu.