Effects of riboflavin on 6,7-dimethyl-8-ribityllumazine formation in growing cells of a riboflavin-adenine-deficient mutant, Bacillus subtilis.
The effects of riboflavin on the formation of 6,7-dimethyl-8-ribityllumazine (DMRL) were examined using the growing cells of a riboflavin, adenine deficient-mutant, Bacillus subtilis. The administration of low concentrations (50-500 ng/mL) of riboflavin to the basal medium significantly inhibited the formation of DMRL without any change in growth. Especially, the supplementation of more than 250 ng/mL riboflavin completely restricted the formation of DMRL under the experimental conditions. The results clearly indicate that a rigid negative feedback inhibition is operative for the biosynthetic pathway of riboflavin in B. subtilis.
Nakajima
Kenji
K
Laboratory of Biochemistry, Faculty of Nutrition, Koshien University, Takarazuka, Hyogo 666-0006, Japan. nakajima@koshien.ac.jp
D000225:Adenine / Q000502:physiology*; D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism*; D025461:Feedback, Physiological; D009154:Mutation; D011621:Pteridines / Q000378:metabolism*; D012256:Riboflavin / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*
D011621:Pteridines; C001061:6,7-dimethyl-8-ribityllumazine; D000225:Adenine; D012256:Riboflavin