Isolation of a pdxJ point mutation that bypasses the requirement for the PdxH oxidase in pyridoxal 5' -phosphate coenzyme biosynthesis in Escherichia coli K-12.

We isolated 26 suppressor mutations that allowed growth of a delta pdxH::omega null mutant in the absence of pyridoxal. Each suppressor mapped to pdxJ, and the eight suppressors sequenced contained the same glycine-to-serine change in the PdxJ polypeptide. This bypass suppression suggests that PdxJ may participate in formation of the pyridine ring of pyridoxine 5'-phosphate.