{PDOC00581} {PS51177; LUMAZINE_BIND} {BEGIN} ******************************************************************* * Riboflavin synthase alpha chain lumazine-binding repeat profile * ******************************************************************* Riboflavin synthase (RS-alpha) catalyzes the biosynthesis of riboflavin (vitamin B2) by dismutation of 6,7-dimethyl-8-(1'-D-ribityl)lumazine (Lum) (EC 2.5.1.9). Riboflavin synthases of bacteria and fungi are structurally and evolutionary related to antenna proteins involved in bioluminescence of marine bacteria [1,2]. These proteins seem to have evolved from the duplication of a domain of about 100 residues, the lumazine-binding repeat. The 3D structure of RS-alpha, which is an asymmetric homotrimer, shows that both domains form a 6-stranded antiparallel beta-barrel (see ) [3], while a C-terminal helix is involved in trimerization. The Lum-binding domain of RS-alpha forms two Greek-key folds with the topology BBHBBBHB, where most of the substrate binding sites are located in beta-strands (B) 4 and 5 and in helix (H) 2 [3-5]. Some proteins known to contain a lumazine-binding repeat: - Riboflavin synthase alpha chain (EC 2.5.1.9) (gene ribC in Escherichia coli, ribB in Bacillus subtilis and Photobacterium leiognathi, RIB5 in yeast). This enzyme synthesizes riboflavin from two molecules of Lum, a pteridine-derivative. - Photobacterium phosphoreum lumazine protein (LumP) (gene luxL). LumP is a protein that modulates the color of the bioluminescence emission of bacterial luciferase. In the presence of LumP, light emission is shifted to higher energy values (shorter wavelength). LumP binds non-covalently to 6,7-dimethyl-8-(1'-D-ribityl)lumazine. - Vibrio fischeri yellow fluorescent protein (YFP) (gene luxY). Like LumP, YFP modulates light emission but towards a longer wavelength. YFP binds non-covalently to FMN. The profile we developed covers the entire lumazine-binding repeat. -Sequences known to belong to this class detected by the profile: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Last update: December 2005 / Pattern removed, profile added and text revised. [ 1] O'Kane D.J., Woodward B., Lee J., Prasher D.C. "Borrowed proteins in bacterial bioluminescence." Proc. Natl. Acad. Sci. U.S.A. 88:1100-1104(1991). PubMed=1996310 [ 2] O'Kane D.J., Prasher D.C. "Evolutionary origins of bacterial bioluminescence." Mol. Microbiol. 6:443-449(1992). PubMed=1560772; [ 3] Meining W., Eberhardt S., Bacher A., Ladenstein R. "The structure of the N-terminal domain of riboflavin synthase in complex with riboflavin at 2.6A resolution." J. Mol. Biol. 331:1053-1063(2003). PubMed=12927541 [ 4] Truffault V., Coles M., Diercks T., Abelmann K., Eberhardt S., Luttgen H., Bacher A., Kessler H. "The solution structure of the N-terminal domain of riboflavin synthase." J. Mol. Biol. 309:949-960(2001). PubMed=11399071; DOI=10.1006/jmbi.2001.4683 [ 5] Gerhardt S., Schott A.K., Kairies N., Cushman M., Illarionov B., Eisenreich W., Bacher A., Huber R., Steinbacher S., Fischer M. "Studies on the reaction mechanism of riboflavin synthase: X-ray crystal structure of a complex with 6-carboxyethyl-7-oxo-8-ribityllumazine." Structure 10:1371-1381(2002). PubMed=12377123 -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}