Mutational analysis of serine-glycine biosynthesis in Rhodopseudomonas capsulata.

Rhodopseudomonas capsulata possesses the enzymes of both the "phosphorylated" and the "non-phosphorylated" pathways of serine biosynthesis. Certain mutants with lesions in the phosphorylated pathway are serine-glycine auxotrophs, though they still produce enzymes of the non-phosphorylated sequence. These results indicate that the phosphorylated pathway is essential for the synthesis of serine and glycine in R. capsulata under the condtions tested.