title: RNA-guided nucleotide modification of ribosomal and non-ribosomal RNAs in Archaea.
abstract: Archaea use ribonucleoprotein (RNP) machines similar to those found in the eukaryotic nucleolus to methylate ribose residues in nascent ribosomal RNA. The archaeal complex required for this 2'-O-ribose-methylation consists of the C/D box sRNA guide and three proteins, the core RNA-binding aL7a protein, the aNop56 protein and the methyltransferase aFib protein. These RNP machines were reconstituted in vitro from purified recombinant components, and shown to have methylation activity when provided with a simple target oligonucleotide, complementary to the sRNA guide sequence. To obtain a better understanding of the versatility and specificity of this reaction, the activity of reconstituted particles on more complex target substrates, including 5S RNA, tRNA(Gln) and 'double target' oligonucleotides that exhibit either direct or reverse complementarity to both the D' and D box guides, has been examined. The natural 5S and tRNA(Gln) substrates were efficiently methylated in vitro, as long as the complementarity between guide and target was about 10 base pairs in length, and lacked mismatches. Maximal activity of double guide sRNAs required that both methylation sites be present in cis on the target RNA.
authors.affiliation: Department of Biochemistry and Molecular Biology University of British Columbia 2146 Health Sciences Mall Vancouver, BC, V6T 1Z3, Canada.
authors.forename: Sonia M
authors.initials: SM
authors.lastname: Ziesche
authors.forename: Arina D
authors.initials: AD
authors.lastname: Omer
authors.forename: Patrick P
authors.initials: PP
authors.lastname: Dennis
mesh_terms: D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D008745:Methylation; D009690:Nucleic Acid Conformation; D019642:RNA, Archaeal / Q000235:genetics* / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000235:genetics* / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism; D016945:Sulfolobus acidocaldarius / Q000235:genetics
chemical_list: D019843:Archaeal Proteins; D019642:RNA, Archaeal; D012335:RNA, Ribosomal; D012346:RNA, Transfer, Amino Acyl; D011994:Recombinant Proteins; D012261:Ribonucleoproteins