ИСТИНА

During last several years, more and more high resistant bacteria were being discovered. At the same time, it is already known pathogenic bacteria gained resistance genes. As a result, it caused gradual decrease in the efficiency of known antibiotics. According to WHO data, by 2050 it is expected that mortality rate caused by bacterial diseases will increase from 0,7 million to 10 million annually. Therefore, searching for novel compounds with antibiotic activity is extremely important as well as understanding its mechanism of action. In the result of screening a significant antibiotic activity for cultural broth sample of bacterium Amycoloplasis sp. was shown. An active substance was purified (by HPLC method) and identified by mass spectroscopy and by UV-spectrometry methods as an already known substance named Tetracenomycin X (TcmX). In the only paper describing probable mechanism of action of TcmX, it was shown that this substance does not cause stalling of translation on polyU template. According to this data authors concluded that TcmX probably acts as an intercalating antibiotic. However, data obtained using reporter strain E.coli pDualrep2 allowed us to suppose translational inhibition as a probable mechanism of antibiotic activity. This suggestion was proved by an ability of purified TcmX to translational inhibition in vitro. Afterwards 32P toe- printing method demonstrated an inhibition of translation and formed a hypothesis that interruption of translation happens on an elongation stage.