[Relationship between aminoacyl-tRNA synthetases (AAA) and cell division in temperature-sensitive filamentous mutants of Bacillus subtilis SB 19. III. Characterization of pre-incubation effect and effect of AAA-inhibitor produced by Agrostemma githago seedlings].

Further results on the correlations between the regulation of bacterial cell division and amino-acyl-tRNA synthetase are presented. Activity of aminoacyl-tRNA synthetases, extracted from a filamentous mutant of Bacillus subtilis SB 19, may be stimulated by preincubation of crude extracts. The mechanism of this stimulating effect has been studied by means of an inhibitor of amino-acyl-tRNA synthetases produced during the growth of Agrostemma githago-seedlings. According to preliminary results we suggest, this inhibitor can reduce the activity of subunits only, but not that of higher associates. Association of subunits to oligomers will be prevented by the inhibitor, too. Our results may be indicative of the assumption that the increase of enzyme activity during subunits with a low catalytic activity to functional oligomers. As to the verification of these hypotheses further work will still have to be done.