home *** CD-ROM | disk | FTP | other *** search
- *********************************************************************
- * Riboflavin synthase alpha chain family Lum-binding site signature *
- *********************************************************************
-
- The following bacterial proteins have been shown [1,2] to be structurally and
- evolutionary related:
-
- - Riboflavin synthase alpha chain (EC 2.5.1.9) (RS-alpha) (gene riBC in
- Escherichia coli and ribB in Bacillus subtilis). This enzyme synthesizes
- riboflavin from two moles of 6,7-dimethyl-8-(1'-D-ribityl)lumazine (Lum), a
- pteridine-derivative.
- - Photobacterium phosphoreum lumazine protein (LumP) (gene luxL). LumP is a
- protein that modulates the color of the bioluminescence emission of the
- 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 in the direction of a longer wavelength.
- YFP binds non-covalently to FMN.
-
- These proteins seem to have evolved from the duplication of a domain of about
- 100 residues. This domain contains, in its C-terminal section a conserved
- motif [KR]-V-N-[LI]-E which has been proposed to be the binding site for Lum.
- RS-alpha which binds two molecules of Lum has two perfect copies of this
- motif, while LumP which binds to one molecule of Lum has a Glu instead of Lys/
- Arg in the first position of the second copy of the motif. Similarily, YFP
- which binds to one molecule of FMN, also seems to have a potentially
- dysfunctional binding site by substitution of Gly for the Glu in the last
- position of the first copy of the motif.
-
- Our signature pattern includes the Lum-binding motif.
-
- -Consensus pattern: [LIVMF]-x(5)-G-[ASDNQ]-[KREW]-V-N-[LIVM]-E
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: rat cysteine dioxygenase.
- -Last update: October 1993 / Pattern and text revised.
-
- [ 1] O'Kane D.J., Woodward B., Lee J., Prasher D.C.
- Proc. Natl. Acad. Sci. U.S.A. 88:1100-1104(1991).
- [ 2] O'Kane D.J., Prasher D.C.
- Mol. Microbiol. 6:443-449(1992).
-