Structural highlights
Function
[RIB4_YEAST] Catalyzes the formation of 6,7-dimethyl-8-ribityllumazine by condensation of 5-amino-6-(D-ribitylamino)uracil with 3,4-dihydroxy-2-butanone 4-phosphate. This is the penultimate step in the biosynthesis of riboflavin.[1] [2]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Lumazine synthase of Saccharomyces cerevisiae is a homopentamer with a molecular weight of 90 kDa. Crystals of the recombinant enzyme with a size of up to 1.6 mm were obtained. The space group is P4(1)2(1)2 with lattice dimensions 82.9 A x 82.9 A x 300.2 A. X-ray diffraction data collected under cryogenic conditions were complete to 1.85 A resolution. The structure of the enzyme in complex with the intermediate analogue, 5-(6-D-ribitylamino-2,4-dihydroxypyrimidine-5-yl)-1-pentyl-p hosphonic acid was solved via molecular replacement using the structure of the Bacillus subtilis enzyme as search model and was refined to a final R-factor of 19.8% (Rfree: 22.5%). The conformation of the active site ligand of the enzyme mimicks that of the Schiff base intermediate of the enzyme-catalyzed reaction. The data enable the reconstruction of the reactant topology during the early steps of the catalytic reaction. Structural determinants, which are likely to be responsible for the inability of the S. cerevisiae enzyme to form icosahedral capsids, will be discussed.
The atomic structure of pentameric lumazine synthase from Saccharomyces cerevisiae at 1.85 A resolution reveals the binding mode of a phosphonate intermediate analogue.,Meining W, Mortl S, Fischer M, Cushman M, Bacher A, Ladenstein R J Mol Biol. 2000 May 26;299(1):181-97. PMID:10860731[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Garcia-Ramirez JJ, Santos MA, Revuelta JL. 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. 1995 Oct 6;270(40):23801-7. PMID:7559556
- ↑ Mortl S, Fischer M, Richter G, Tack J, Weinkauf S, Bacher A. Biosynthesis of riboflavin. Lumazine synthase of Escherichia coli. J Biol Chem. 1996 Dec 27;271(52):33201-7. PMID:8969176
- ↑ Meining W, Mortl S, Fischer M, Cushman M, Bacher A, Ladenstein R. The atomic structure of pentameric lumazine synthase from Saccharomyces cerevisiae at 1.85 A resolution reveals the binding mode of a phosphonate intermediate analogue. J Mol Biol. 2000 May 26;299(1):181-97. PMID:10860731 doi:10.1006/jmbi.2000.3742
