RNase P
From Wikipedia, the free encyclopedia
RNase P is a type of ribonuclease and is currently under heavy research. RNase P is unique from other RNases in that it is a ribozyme – a ribonucleic acid that acts as a catalyst in the same way that a protein based enzyme would. Its function is to cleave off an extra, or precursor, sequence of RNA on tRNA molecules. Further RNase P is one of two known multiple turnover ribozymes in nature (the other being the ribosome), the discovery of which earned Sidney Altman the Nobel Prize in Chemistry in 1989.
In bacteria, such as E. coli, RNase P has two components: an RNA chain, called M1 RNA, and a polypeptide chain, or protein, called C5 protein. In vivo, both components are necessary for the ribozyme to function properly, but in vitro, the M1 RNA can act alone as a catalyst.
In eukaryotes, such as humans and yeast, RNase P consists of an RNA chain similar to that found in bacteria as well as about ten associated proteins (as opposed to the single bacterial RNase P protein). RNase P from eukaryotes has not yet been directly demonstrated to be a ribozyme, although it is commonly hypothesized to be.
