Mechanistic Studies Reveal Similar Catalytic Strategies for Phosphodiester Bond Hydrolysis by Protein-only and RNA-dependent Ribonuclease P.

ABSTRACT: Ribonuclease P (RNase P) is an endonuclease that catalyzes the essential removal of the 5' end of tRNA precursors. Until recently, all identified RNase P enzymes were a ribonucleoprotein with a conserved catalytic RNA component. However, the discovery of protein-only RNase P (PRORP) shifted this paradigm, affording a unique opportunity to compare mechanistic strategies used by naturally evolved protein and RNA-based enzymes that catalyze the same reaction. Here we investigate the enzymatic mechanism of pre-tRNA hydrolysis catalyzed by the NYN (Nedd4-BP1, YacP nuclease) metallonuclease of Arabidopsis thaliana, PRORP1. Multiple and single turnover kinetic data support a mechanism where a step at or before chemistry is rate-limiting and provide a kinetic framework to interpret the results of

SUBMITTER: Howard MJ 

PROVIDER: S-EPMC4505592 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature