title: Initiation of Bacillus subtilis sporulation by the stringent response to partial amino acid deprivation.
abstract: We have controlled the rates at which three different amino acids were available to auxotrophs of Bacillus subtilis by avoiding active transport of the respective substrate. The active transport of oxomethylvalerate, a precursor of isoleucine, was prevented by a kauA mutation, the uptake of L-aspartate was competed by 20 mM L-glutamate, and D-methionine was used instead of L-methionine. When in this way conditions of partial amino acid deprivation were achieved, a partial "stringent response" occurred which included the increase of ppGpp and pppGpp, and the decrease of GTP; such conditions initiated sporulation. In the corresponding relaxed (relA) mutants, the changes of guanine nucleotides were greatly reduced and no sporulation was observed at any substrate concentration; but addition of decoyinine produced a further decrease of GTP and caused sporulation.
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D001224:Aspartic Acid / Q000378:metabolism; D001412:Bacillus subtilis / Q000254:growth & development / Q000378:metabolism*; D001692:Biological Transport; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D007700:Kinetics; D008715:Methionine / Q000378:metabolism; D009154:Mutation; D013045:Species Specificity; D013171:Spores, Bacterial / Q000378:metabolism
chemical_list: D000596:Amino Acids; D005971:Glutamates; D001224:Aspartic Acid; D018698:Glutamic Acid; D008715:Methionine