title: Biosynthesis of riboflavin. Enzymatic formation of the xylene moiety from [14C]ribulose 5-phosphate.
abstract: We have studied the enzymatic formation of the xylene ring of riboflavin using cell extracts from the flavinogenic yeast Candida guilliermondii. 5-Amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione or its 5'-phosphate could serve as substrates. In addition, a pentose phosphate or pentulose phosphate was required. Experiments with [14C]ribulose 5-phosphate gave evidence for the incorporation of the ribulose carbon atoms except C-4 into the xylene ring of the vitamin.
mesh_terms: D002175:Candida / Q000201:enzymology*; D010428:Pentosephosphates / Q000378:metabolism*; D012256:Riboflavin / Q000096:biosynthesis*; D012274:Ribulosephosphates / Q000378:metabolism*; D013379:Substrate Specificity; D014500:Uracil Nucleotides / Q000378:metabolism; D014529:Uridine / Q000031:analogs & derivatives / Q000378:metabolism; D014992:Xylenes / Q000378:metabolism*
chemical_list: C040524:5-amino-6-ribitylamino-2,4(1H,3H)pyrimidinedione 5'-phosphate; D010428:Pentosephosphates; D012274:Ribulosephosphates; D014500:Uracil Nucleotides; D014992:Xylenes; C040523:5-amino-6-ribitylamino-2,4-(1H,3H)pyrimidinedione; C031524:ribulose 5-phosphate; D012256:Riboflavin; D014529:Uridine