Poster abstracts

Poster number 5 submitted by Junjun Chen

The Molecular Recognition of RNA by the Pseudouridine Synthase RluA: Kinetic and Crystallographic Studies

Junjun Chen (Department of Chemistry and Biochemisry, University of Delaware), Charmaine Hoang (Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle), Adrian R. Ferré-D'Amaré (Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle), Eugene G. Mueller (Department of Chemistry and Biochemisry, University of Delaware)

Abstract:
Pseudouridine synthases (Ψ synthases) catalyze the isomerization of uridine to pseudouridine (Ψ) and are present in all domains of life. The Ψ synthases fall into five families, and crystal structure of members of each family show that they share the same core fold. The cocrystal structure of the E. coli Ψ synthase RluA bound to an RNA oligomer corresponding to the anticodon stem-loop (ASL) of E. coli tRNA^Phe has recently been determined by us (Hoang, C., et al., and Ferre-D'Amare, Mol. Cell, in press). This structure is only the second of a Ψ synthase bound to an RNA substrate. In the RluA-RNA cocrystal, the RNA has undergone significant conformational changes from its unbound form due to protein-RNA interactions. To test the importance of particular interactions in the RluA-ASL cocrystal structure, the enzymatic activity of RluA towards seven altered ASLs was measured. These kinetic studies are presented along with the active site structure.

Keywords: pseudouridine synthase, RluA, RNA recognition