Studies on Bacterial Spore Ultraviolet Light Resistance and Regulation of theActivity of a Spore Protease

摘要

Highlights of the most significant research finding in the last few years are:(1) alpha/beta-type SASP have been shown in vitro to be a novel group of non-specific, double-strand DNA binding proteins which slow DNA depurination, block hydroxyl-radical cleavage of the backbone, and block UV induced pyrimidine dimer formation, while promoting spore photoproduct formation; (2) the effects of alpha/beta-type SASP in vitro are also exerted in vivo as these proteins are important factors in spore heat and hydrogen peroxide resistance, and the major cause of spore UV resistance; (3) studies of the regulation and processing of the SASP specific protease have strongly suggested that the processing of the zymogen form of this enzyme during sporulation is an autocatalyzed event triggered by changes in the forespore (very likely dehydration) which will block attack of the active enzyme on SASP. In the first minutes of spore germination spore core rehydration then allows rapid SASP degradation. Bacterial spore, Radiation resistance, Heat resistance, Spore germination, Proteolysis.