Biosynthesis of riboflavin

• Published in: Cofactor Biosynthesis: a Mechanistic Perspective Vol. 61; pp. 1 - 49
• Main Authors: Bacher, Adelbert, Eberhardt, Sabine, Eisenreich, Wolfgang, Fischer, Markus, Herz, Stefan, Illarionov, Boris, Kis, Klaus, Richter, Gerald
• Format: Book Chapter Journal Article
• Language: English
• Published: United States Elsevier Science & Technology 2001; Academic Press
• Subjects: Analytical, structural and metabolic biochemistry; Animal physiology; Bacillus subtilis - enzymology; Bacillus subtilis - genetics; biochemical pathways; Biochemistry; Biological and medical sciences; biosynthesis; Coenzymes, vitamins; Endocrinology; enzymes; Fermentation; Fundamental and applied biological sciences. Psychology; Humans; Kinetics; Other biological molecules; riboflavin; Riboflavin - antagonists & inhibitors; Riboflavin - biosynthesis; Riboflavin - chemistry; Riboflavin Synthase - chemistry; Riboflavin Synthase - metabolism; Yeast; Enzyme; Metabolic cycle; Eubacteria; Vitamin; Riboflavin; Biosynthesis; Review; Synthetic inhibitor; Fungi; Regulation(control); Bacteria; Ascomycetes; Thallophyta
• ISBN: 9780127098616; 0127098615
• ISSN: 0083-6729; 2162-2620
• DOI: 10.1016/S0083-6729(01)61001-X

The biosynthesis of one riboflavin molecule requires one molecule of GTP and two molecules of ribulose 5-phosphate. The imidazole ring of GTP is hydrolytically opened, yielding a 4,5-diaminopyrimidine that is converted to 5-amino-6-ribitylamino-2,4(1 H,3 H)-pyrimidinedione by a sequence of deamination, side chain reduction, and dephosphorylation. Condensation of 5-amino-6-ribitylamino-2,4(1 H,3 H)-pyrimidinedione with 3,4-dihydroxy-2-butanone 4-phosphate obtained from ribulose 5-phosphate affords 6,7-dimethyl-8-ribityllumazine. Dismutation of the lumazine derivative yields riboflavin and 5-amino-6-ribitylamino-2,4(1 H,3 H)-pyrimidinedione, which is recycled in the biosynthetic pathway. Two reaction steps in the biosynthetic pathway catalyzed by 3,4-dihydroxy-2-butanone 4-phosphate synthase and riboflavin synthase are mechanistically very complex. The enzymes of the riboflavin pathway are potential targets for antibacterial agents.