title: Ribonucleases P/MRP and the expanding ribonucleoprotein world.
abstract: One of the hallmarks of life is the widespread use of certain essential ribozymes. The ubiquitous ribonuclease P (RNase P) and eukaryotic RNase MRP are essential complexes where a structured, noncoding RNA acts in catalysis. Recent discoveries have elucidated the three-dimensional structure of the ancestral ribonucleoprotein complex, suggested the possibility of a protein-only composition in organelles, and even noted the absence of RNase P in a non-free-living organism. With respect to these last two findings, import mechanisms for RNases P/MRP into mitochondria have been demonstrated, and RNase P is present in organisms with some of the smallest known genomes. Together, these results have led to an ongoing debate regarding the precise definition of how "essential" these ribozymes truly are.
authors.affiliation: Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico.
authors.forename: Aaron
authors.initials: A
authors.lastname: Hernandez-Cid
authors.forename: Sergio
authors.initials: S
authors.lastname: Aguirre-Sampieri
authors.forename: Adelaida
authors.initials: A
authors.lastname: Diaz-Vilchis
authors.forename: Alfredo
authors.initials: A
authors.lastname: Torres-Larios
mesh_terms: D000818:Animals; D020134:Catalytic Domain; D004722:Endoribonucleases / Q000737:chemistry / Q000502:physiology*; D019143:Evolution, Molecular; D006801:Humans; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry / Q000235:genetics; D043262:Ribonuclease P / Q000737:chemistry / Q000502:physiology*; D012261:Ribonucleoproteins / Q000737:chemistry / Q000502:physiology*
chemical_list: D012261:Ribonucleoproteins; D012313:RNA; D004722:Endoribonucleases; C058330:mitochondrial RNA-processing endoribonuclease; D043262:Ribonuclease P