Physical and enzymological interaction of Bacillus subtilis proteins required for de novo pyridoxal 5'-phosphate biosynthesis.
Bacillus subtilis synthesizes pyridoxal 5'-phosphate, the active form of vitamin B(6), by a poorly characterized pathway involving the yaaD and yaaE genes. The pdxS (yaaD) mutant was confirmed to be a strict B(6) 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 B(6) biosynthesis.
Belitsky
Boris R
BR
Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA. bbelit02@granite.tufts.edu
D000878:Anthranilate Synthase; D001412:Bacillus subtilis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000502:physiology*; D001483:Base Sequence; D008969:Molecular Sequence Data; D009154:Mutation; D019884:Nitrogenous Group Transferases / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D011732:Pyridoxal Phosphate / Q000096:biosynthesis*
D001426:Bacterial Proteins; D011732:Pyridoxal Phosphate; D019884:Nitrogenous Group Transferases; D000878:Anthranilate Synthase; C020655:anthranilate synthase, glutamine amidotransferase subunit