Poster abstracts

Poster number 48 submitted by Larry Layne

In vitro selection of co-enzyme dependent nucleic acid enzymes

Larry Layne (Chemistry Department, Carnegie Mellon University), Eduardo Paredes (Chemistry Department, Carnegie Mellon University), Subha R. Das (Chemistry Department, Carnegie Mellon University)

Abstract:
Glucosamine-6-phosphate (GlcN6P) required for cell wall synthesis in all gram-positive bacteria is regulated at the RNA level by the conserved glmS riboswitch. The glmS riboswitch is the only known natural ribozyme that uses GlcN6P as a putative co-enzyme to catalyze RNA cleavage. Co-enzyme dependent RNA cleavage remains an underexplored area in nucleic acid catalysis. We are currently investigating the use of co-enzymes and co-factors by nucleic acid enzymes and are selecting for DNA sequences that will catalyze RNA cleavage with GlcN6P as a co-enzyme. In order to distinguish between a structural versus chemical requirement for GlcN6P in catalysis, we also perform a negative selection with glucose-6-phosphate (Glc6P), which lacks a protonatable putative general acid. Following selections, two pools of DNAzymes, one dependent upon GlcN6P, and the other upon Glc6P, will be obtained. The catalytic mechanism and role of the co-enzyme in the obtained DNAzymes will be investigated.

Keywords: SELEX, DNAzyme, glmS ribozyme