Physical and Enzymological Interaction of Bacillus subtilis Proteins Required for De Novo Pyridoxal 5′-Phosphate Biosynthesis

AUTOR(ES)

Belitsky, Boris R.

FONTE

American Society for Microbiology

RESUMO

Bacillus subtilis synthesizes pyridoxal 5′-phosphate, the active form of vitamin B6, by a poorly characterized pathway involving the yaaD and yaaE genes. The pdxS (yaaD) mutant was confirmed to be a strict B6 auxotroph, but the pdxT (yaaE) mutant turned out to be a conditional auxotroph depending on the availability of ammonium in the growth medium. The PdxS and PdxT proteins copurified during affinity chromatography and apparently form a complex that has glutaminase activity. PdxS and PdxT appear to encode the synthase and glutaminase subunits, respectively, of a glutamine amidotransferase of as-yet-unknown specificity essential for B6 biosynthesis.

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