ANALYSIS OF THE TERTIARY STRUCTURE OF BACTERIAL RNASE-P RNA

The ubiquitous occurrence of ribonuclease P (RNase P) as a ribonucleop rotein and the catalytic properties of bacterial RNase P RNAs indicate that RNA fulfills an ancient and important role in the function of th is enzyme. This review focuses on efforts to determine the structure o f the bacterial RNase P RNA ribozyme. Phylogenetic comparative analysi s of a library of bacterial RNase P RNA sequences has resulted in a we ll-developed secondary structure model and allowed identification of s ome elements of tertiary structure. The native structure has been rede signed by circular permutation to facilitate intra- and inter-molecula r crosslinking experiments in order to gain further structural informa tion. The crosslinking constraints, together with the constraints prov ided by comparative analyses, have been incorporated into a first-orde r model of the structure of the ribozyme-substrate complex. The develo ping structural perspective allows the design of self-cleaving pre-tRN A-RNase P RNA conjugates which are useful tools for additional structu re-probing experiments.