title: Nuclear RNase P of Trypanosoma brucei: a single protein in place of the multicomponent RNA-protein complex.
abstract: RNase P is the endonuclease that removes 5' extensions from tRNA precursors. In its best-known form, the enzyme is composed of a catalytic RNA and a protein moiety variable in number and mass. This ribonucleoprotein enzyme is widely considered ubiquitous and apparently reached its highest complexity in the eukaryal nucleus, where it is typically composed of at least ten subunits. Here, we show that in the protist Trypanosoma brucei, two proteins are the sole forms of RNase P. They localize to the nucleus and the mitochondrion, respectively, and have RNase P activity each on their own. The protein-RNase P is, moreover, capable of replacing nuclear RNase P in yeast cells. This shows that complex ribonucleoprotein structures and RNA catalysis are not necessarily required to support tRNA 5' end formation in eukaryal cells.
authors: Center for Anatomy & Cell Biology, Medical University of Vienna, Währinger Straße 13, 1090 Vienna, Austria.
authors: Andreas
authors: A
authors: Taschner
authors: Christoph
authors: C
authors: Weber
authors: Aurélie
authors: A
authors: Buzet
authors: Roland K
authors: RK
authors: Hartmann
authors: Andreas
authors: A
authors: Hartig
authors: Walter
authors: W
authors: Rossmanith
mesh_terms: D002467:Cell Nucleus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D017125:Genes, Protozoan / Q000502:physiology; D018503:Genome, Protozoan; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D046912:Multiprotein Complexes / Q000502:physiology; D030781:Organisms, Genetically Modified; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D043262:Ribonuclease P / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014346:Trypanosoma brucei brucei / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D015003:Yeasts / Q000201:enzymology / Q000235:genetics / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D046912:Multiprotein Complexes; D015800:Protozoan Proteins; D043262:Ribonuclease P