title: Nuclear RNase MRP processes RNA at multiple discrete sites: interaction with an upstream G box is required for subsequent downstream cleavages.
abstract: RNase MRP is a site-specific endoribonuclease that processes primer RNA from the leading-strand origin of mammalian mitochondrial DNA replication. It is present in active form as isolated from the nucleus, suggesting a bipartite cellular location and function. The relatively high abundance of nucleus-localized RNase MRP has permitted its purification to near homogeneity and, in turn, has led to the identification of protein components of this ribonucleoprotein. Analysis of the mode of RNA cleavage by nuclear RNase MRP revealed the surprising and unprecedented ability of the endonuclease to process RNA at multiple discrete locations. Substrate cleavage is dependent on the presence of a previously described G-rich sequence element adjacent to the primary site of RNA processing. Downstream cleavage occur in a distance- and sequence-specific manner.
authors.affiliation: Department of Developmental Biology, Stanford University School of Medicine, California 94305-5427.
authors.forename: R
authors.initials: R
authors.lastname: Karwan
authors.forename: J L
authors.initials: JL
authors.lastname: Bennett
authors.forename: D A
authors.initials: DA
authors.lastname: Clayton
mesh_terms: D000818:Animals; D001482:Base Composition; D001483:Base Sequence; D002467:Cell Nucleus / Q000201:enzymology; D004722:Endoribonucleases / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation; D012323:RNA Processing, Post-Transcriptional; D016337:RNA, Catalytic / Q000235:genetics; D012335:RNA, Ribosomal / Q000378:metabolism; D043262:Ribonuclease P; D012261:Ribonucleoproteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism
chemical_list: D016337:RNA, Catalytic; D012335:RNA, Ribosomal; D012261:Ribonucleoproteins; D004722:Endoribonucleases; C058330:mitochondrial RNA-processing endoribonuclease; C468368:RPP14 protein, human; D043262:Ribonuclease P