title: Efficient RNA 2'-O-methylation requires juxtaposed and symmetrically assembled archaeal box C/D and C'/D' RNPs.
abstract: Box C/D ribonucleoprotein (RNP) complexes direct the nucleotide-specific 2'-O-methylation of ribonucleotide sugars in target RNAs. In vitro assembly of an archaeal box C/D sRNP using recombinant core proteins L7, Nop56/58 and fibrillarin has yielded an RNA:protein enzyme that guides methylation from both the terminal box C/D core and internal C'/D' RNP complexes. Reconstitution of sRNP complexes containing only box C/D or C'/D' motifs has demonstrated that the terminal box C/D RNP is the minimal methylation-competent particle. However, efficient ribonucleotide 2'-O-methylation requires that both the box C/D and C'/D' RNPs function within the full-length sRNA molecule. In contrast to the eukaryotic snoRNP complex, where the core proteins are distributed asymmetrically on the box C/D and C'/D' motifs, all three archaeal core proteins bind both motifs symmetrically. This difference in core protein distribution is a result of altered RNA-binding capabilities of the archaeal and eukaryotic core protein homologs. Thus, evolution of the box C/D nucleotide modification complex has resulted in structurally distinct archaeal and eukaryotic RNP particles.
authors.affiliation: Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695-7622, USA.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Tran
authors.forename: Xinxin
authors.initials: X
authors.lastname: Zhang
authors.forename: E Stuart
authors.initials: ES
authors.lastname: Maxwell
mesh_terms: D001105:Archaea / Q000378:metabolism*; D019843:Archaeal Proteins / Q000737:chemistry / Q000378:metabolism*; D001483:Base Sequence; D008745:Methylation; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D019642:RNA, Archaeal / Q000737:chemistry / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism*
chemical_list: D019843:Archaeal Proteins; D019642:RNA, Archaeal; D012261:Ribonucleoproteins