| Abstract: | In pleiotropic negative glycerol utilization mutants (GlpPI mutants) of Bacillus subitilis, glycerol kinase and sn-glycerol 3-phosphate (G3P) dehydrogenase are noninducible. GlpPI mutants also fail to take up exogenous [14C]G3P. To study the regulation of the glp system in B. subtilis phenotypically, Glp+ revertants were isolated from GlpPI mutants. Four classes of revertants were identified: phenotypically, wild type; R1 type, which contains an informational suppressor, R2 type, which produced G3P dehydrogenase constitutively; and R3 type, with a temperature-sensitive Glp phenotype producing G3P dehydrogenase constitutively at permissive temperature (32 degrees C). The properties of the revertants indicate that the glpPI locus codes for a protein with a positive regulatory function. |
