IUBMB Enzyme Nomenclature


Accepted name: 6,7-dimethyl-8-ribityllumazine synthase

Reaction: 1-deoxy-L-glycero-tetrulose 4-phosphate + 5-amino-6-(D-ribitylamino)uracil = 6,7-dimethyl-8-(D-ribityl)lumazine + 2 H2O + phosphate

For reaction click here and mechanism click here

Glossary: 5-amino-6-(1-D-ribitylamino)pyrimidine-2,4(1H,3H)-dione = 5-amino-6-(1-D-ribitylamino)-2,4-dihydroxypyrimidine = 6-(1-D-ribitylamino)-5-amino-2,4-dihydroxypyrimidine = 6-(1-D-ribitylamino)-5-aminouracil = 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione
6,7-dimethyl-8-(1-D-ribityl)lumazine = 1-deoxy-1-(6,7-dimethyl-2,4-dioxo-3,4-dihydropteridin-8(2H)-yl)-D-ribitol
(S)-2-hydroxy-3-oxobutyl dihydrogen phosphate = (3S)-3-hydroxy-4-(phosphonooxy)butan-2-one = (2S)-2-hydroxy-3-oxobutyl phosphate = L-3,4-dihydroxybutan-2-one 4-phosphate = (S)-3-hydroxy-4-(phosphonooxy)-2-butanone

Other name(s): lumazine synthase, 6,7-dimethyl-8-ribityllumazine synthase 2; 6,7-dimethyl-8-ribityllumazine synthase 1; lumazine synthase 2; lumazine synthase 1; type I lumazine synthase; type II lumazine synthase; RIB4; MJ0303; RibH; Pbls; MbtLS; RibH1 protein; RibH2 protein; RibH1; RibH2

Systematic name: 5-amino-6-(D-ribitylamino)uracil butanedionetransferase

Comments: Involved in riboflavin biosynthesis.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Kis, K., Volk, R. and Bacher, A. Biosynthesis of riboflavin. Studies on the reaction mechanism of 6,7-dimethyl-8-ribityllumazine synthase. Biochemistry 34 (1995) 2883-2892. [PMID: 7893702]

2. Garcia-Ramirez, J.J., Santos, M.A. and Revuelta, J.L. The Saccharomyces cerevisiae RIB4 gene codes for 6,7-dimethyl-8-ribityllumazine synthase involved in riboflavin biosynthesis. Molecular characterization of the gene and purification of the encoded protein. J. Biol. Chem. 270 (1995) 23801-23807. [PMID: 7559556]

3. Bacher, A., Fischer, M., Kis, K., Kugelbrey, K., Mörtl, S., Scheuring, J., Weinkauf, S., Eberhardt, S., Schmidt-Bäse, K., Huber, R., Ritsert, K., Cushman, M., Ladenstein, R. Biosynthesis of riboflavin: structure and mechanism of lumazine synthase. Biochem. Soc. Trans. 24 (1996) 89-94. [PMID: 8674771]

4. Mortl, S., Fischer, M., Richter, G., Tack, J., Weinkauf, S. and Bacher, A. Biosynthesis of riboflavin. Lumazine synthase of Escherichia coli. J. Biol. Chem. 271 (1996) 33201-33207. [PMID: 8969176]

5. Bacher, A., Eberhardt, S., Fischer, M., Mortl, S., Kis, K., Kugelbrey, K., Scheuring, J. and Schott, K. Biosynthesis of riboflavin: lumazine synthase and riboflavin synthase. Methods Enzymol. 280 (1997) 389-399. [PMID: 9211334]

6. Goldbaum, F.A., Velikovsky, C.A., Baldi, P.C., Mortl, S., Bacher, A. and Fossati, C.A. The 18-kDa cytoplasmic protein of Brucella species - an antigen useful for diagnosis- is a lumazine synthase. J Med Microbiol 48 (1999) 833-839. [PMID: 10482294]

7. Jordan, D.B., Bacot, K.O., Carlson, T.J., Kessel, M. and Viitanen, P.V. Plant riboflavin biosynthesis. Cloning, chloroplast localization, expression, purification, and partial characterization of spinach lumazine synthase. J. Biol. Chem. 274 (1999) 22114-22121. [PMID: 10419541]

8. Zhang, X., Meining, W., Fischer, M., Bacher, A. and Ladenstein, R. X-ray structure analysis and crystallographic refinement of lumazine synthase from the hyperthermophile Aquifex aeolicus at 1.6 Å resolution: determinants of thermostability revealed from structural comparisons. J. Mol. Biol. 306 (2001) 1099-1114. [PMID: 11237620]

9. Fischer, M., Haase, I., Feicht, R., Richter, G., Gerhardt, S., Changeux, J.P., Huber, R. and Bacher, A. Biosynthesis of riboflavin: 6,7-dimethyl-8-ribityllumazine synthase of Schizosaccharomyces pombe. Eur. J. Biochem. 269 (2002) 519-526. [PMID: 11856310]

10. Cushman, M., Yang, D., Gerhardt, S., Huber, R., Fischer, M., Kis, K. and Bacher, A. Design, synthesis, and evaluation of 6-carboxyalkyl and 6-phosphonoxyalkyl derivatives of 7-oxo-8-ribitylaminolumazines as inhibitors of riboflavin synthase and lumazine synthase. J. Org. Chem. 67 (2002) 5807-5816. [PMID: 12153285]

11. Haase, I., Mortl, S., Kohler, P., Bacher, A. and Fischer, M. Biosynthesis of riboflavin in archaea. 6,7-dimethyl-8-ribityllumazine synthase of Methanococcus jannaschii. Eur. J. Biochem. 270 (2003) 1025-1032. [PMID: 12603336]

12. Morgunova, E., Meining, W., Illarionov, B., Haase, I., Jin, G., Bacher, A., Cushman, M., Fischer, M. and Ladenstein, R. Crystal structure of lumazine synthase from Mycobacterium tuberculosis as a target for rational drug design: binding mode of a new class of purinetrione inhibitors. Biochemistry 44 (2005) 2746-2758. [PMID: 15723519]

[EC created 2010]

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