Evidence that substrate-specific effects of C5 protein lead to uniformity in binding and catalysis by RNase P.

ABSTRACT: The ribonucleoprotein enzyme RNase P processes all pre-tRNAs, yet some substrates apparently lack consensus elements for recognition. Here, we compare binding affinities and cleavage rates of Escherichia coli pre-tRNAs that exhibit the largest variation from consensus recognition sequences. These results reveal that the affinities of both consensus and nonconsensus substrates for the RNase P holoenzyme are essentially uniform. Comparative analyses of pre-tRNA and tRNA binding to the RNase P holoenzyme and P RNA alone reveal differential contributions of the protein subunit to 5' leader and tRNA affinity. Additionally, these studies reveal that uniform binding results from variations in the energetic contribution of the 5' leader, which serve to compensate for weaker tRNA interactions. Furt

SUBMITTER: Sun L 

PROVIDER: S-EPMC1560353 | biostudies-literature | 2006 Sep

REPOSITORIES: biostudies-literature