title: Ribosomal RNA precursor processing by a eukaryotic U3 small nucleolar RNA-like molecule in an archaeon.
abstract: An RNA-containing endonuclease that catalyzes the excision and maturation of the 16S ribosomal RNA (rRNA) from the rRNA primary transcript (pre-rRNA) in the hyperthermophilic archaeon Sulfolobus acidocaldarius has been characterized. The ribonucleoprotein was inactivated by micrococcal nuclease treatment and inactivation was reversed by reconstitution with bulk RNA. A 159-nucleotide RNA with sequence and structural similarity to U3 small nucleolar RNAs of eukaryotes copurified with the endonuclease activity. Oligonucleotide-targeted ribonuclease H inactivation of the U3-like RNA component also abolished processing activity. A motif within the U3 homolog is complementary to the region around the three cleavage sites in the pre-RNA substrate. Thus, U3-mediated processing of pre-rRNA is not specific to eukaryotes; its origin predates the divergence of archaea and eukaryotes.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Potter
authors.forename: P
authors.initials: P
authors.lastname: Durovic
authors.forename: P P
authors.initials: PP
authors.lastname: Dennis
mesh_terms: D001483:Base Sequence; D002466:Cell Nucleolus / Q000235:genetics; D004722:Endoribonucleases / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012322:RNA Precursors / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional / Q000502:physiology*; D012329:RNA, Bacterial / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000378:metabolism*; D012342:RNA, Small Nuclear / Q000378:metabolism; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D016945:Sulfolobus acidocaldarius / Q000235:genetics*
chemical_list: D012322:RNA Precursors; D012329:RNA, Bacterial; D012335:RNA, Ribosomal; D012342:RNA, Small Nuclear; D017411:Ribonucleoproteins, Small Nuclear; D004722:Endoribonucleases