Escherichia coli ribonuclease P.

Publisher Summary Ribonuclease P is an endoribonuclease responsible for the maturation of the 5′ termini of the majority of all known tRNAs in all cell types studied to date. In Escherichia coli, RNase P consists of an RNA subunit, Ml RNA, and a small basic protein, C5. The catalytic activity is associated with M1 RNA, and cleavage of various substrates In Vitro does not require the presence of the C5 protein. Although this chapter focuses on E. coli RNase P, other bacterial RNase P systems such as that of Bacillus subtilis have also been studied in detail. Protocols for in vitro studies of RNase P activity have been described and an experimental system that can be used to study tRNA processing with an emphasis on RNase P in vivo have been discussed. Genetics is a powerful tool to understand the function of an enzyme and this is also applicable in studies of the function of RNase P. Thus, a large number of mutant substrates and M1 RNA derivatives have been generated. To introduce modified nucleotides at specific positions either in the substrate or in M1 RNA different approaches can be taken.