title: B-factor, an essential regulatory substance inducing the production of rifamycin in a Nocardia sp.
abstract: "Curing" treatment of a rifamycin-producing Nocardia sp. resulted in a mutant deficient in the synthesis of antibiotics. This deficiency was reversed in a medium containing yeast extract. The active substance, named B-factor, which induced rifamycin production in the mutant was purified from yeast extract, and its structure, 3'-(1-butylphosphoryl) adenosine, was determined by structural analysis and chemical synthesis. An extremely low concentration of B-factor (10 ng/ml) caused recovery of rifamycin B synthesis in the mutant and stimulated synthesis of the antibiotic in the parental strain.
mesh_terms: D000249:Adenosine Monophosphate / Q000031:analogs & derivatives* / Q000302:isolation & purification; D055598:Chemical Phenomena; D002621:Chemistry; D009682:Magnetic Resonance Spectroscopy; D009154:Mutation; D009615:Nocardia / Q000378:metabolism*; D012294:Rifamycins / Q000096:biosynthesis*
chemical_list: D012294:Rifamycins; D000249:Adenosine Monophosphate; C044533:3'-(1-butylphosphoryl)adenosine