Biosynthesis of riboflavin. An aliphatic intermediate in the formation of 6,7-dimethyl-8-ribityllumazine from pentose phosphate.
6,7-Dimethyl-8-ribityllumazine synthase deficient mutants of Candida guilliermondii were divided into two groups on the basis of in vitro complementation. Mutants of complementation group I produce an intermediate X from ribose 5-phosphate in a reaction requiring Mg++ ions. Compound X was partially purified and was shown to be a phosphoric acid ester. 6,7-Dimethyl-8-ribityllumazine can be formed from Compound X by cell extracts from mutants of complementation group II. The reaction requires 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione or its 5'-phosphate as second substrate. No divalent cations are required.
D002175:Candida / Q000235:genetics / Q000378:metabolism; D002848:Chromatography, DEAE-Cellulose; D009097:Multienzyme Complexes / Q000378:metabolism; D009154:Mutation; D010428:Pentosephosphates / Q000378:metabolism*; D011621:Pteridines / Q000378:metabolism*; D012256:Riboflavin / Q000096:biosynthesis*
D009097:Multienzyme Complexes; D010428:Pentosephosphates; D011621:Pteridines; C001061:6,7-dimethyl-8-ribityllumazine; C044822:6,7-dimethyl-8-ribityllumazine synthase; D012256:Riboflavin