[Possibility of DNA-ligase participation in regulating the synthesis and degradation of heat-damaged DNA in permeable Bacillus stearothermophilus cells].

The chromosome of Bacillus stearothermophilus was found to contain apurine regions which were repaired mainly by excisions. In the permeable cells of the thermophilic bacterium, the observed intensive degradation and resynthesis of DNA were regulated by active DNA ligase. In this case, NAD (the cofactor of ligase) sharply inhibited the ATP-dependent and independent synthesis of DNA. Apparently, DNA ligase may be involved in the regulation of degradation and resynthesis of DNA with thermal lesions in the cells of thermophilic organisms.