Pattern of valine transfer ribonucleic acid of Bacillus subtilis under different growth conditions.

The relative amounts of two valyl-tRNA species from Bacillus subtilis W23 were compared by methylated albumin Kieselguhr column chromatography and by diethylaminoethyl cellulose column chromatography after T1 ribonuclease digestion. The ratio of the two valyl-tRNAs changes significantly during sporulation, during step-up and step-down growth transitions, during the stationary phase of an asporogenous mutant, and during sporulation of B. subtilis 168 Marburg. The change in ratio could not be induced in vitro by treating the tRNA preparations with several chemicals and was not the result of differential hydrolysis of the two valyl-tRNA species during the experimental procedures. The change in ratio was due to the increased valine-accepting ability of one of the two valine tRNAs. These results suggest that the valyl-tRNA ratio changes may be a function of the growth condition and that a regulatory mechanism exists which controls the amino acid accepting capacity of the two valine accepting tRNAs.