Adenine nucleotide synthesis and growth rate of the adenyl succinate lyase mutant of Bacillus anthracis.

After mutations affecting the de novo adenine nucleotide synthesis in Bacillus anthracis, the salvage pathway failed to ensure growth at the prototroph level. In sonicated suspensions of adenyl succinate lyase deficient B. anthracis mutant, in the presence of exogenous 5-phosphoribosyl-1-pyrophosphate (PRPP), part of the labelled adenine was incorporated into adenine nucleotides. Addition of PRPP to cultures of adenyl succinate lyase and adenyl succinate synthetase mutants failed to promote growth. Both kinds of auxotroph showed in vitro a reduced growth rate as compared to the prototrophic strain.