title: RNA-specific ribonucleotidyl transferases.
abstract: RNA-specific nucleotidyl transferases (rNTrs) are a diverse family of template-independent polymerases that add ribonucleotides to the 3'-ends of RNA molecules. All rNTrs share a related active-site architecture first described for DNA polymerase beta and a catalytic mechanism conserved among DNA and RNA polymerases. The best known examples are the nuclear poly(A) polymerases involved in the 3'-end processing of eukaryotic messenger RNA precursors and the ubiquitous CCA-adding enzymes that complete the 3'-ends of tRNA molecules. In recent years, a growing number of new enzymes have been added to the list that now includes the "noncanonical" poly(A) polymerases involved in RNA quality control or in the readenylation of dormant messenger RNAs in the cytoplasm. Other members of the group are terminal uridylyl transferases adding single or multiple UMP residues in RNA-editing reactions or upon the maturation of small RNAs and poly(U) polymerases, the substrates of which are still not known. 2'-5'Oligo(A) synthetases differ from the other rNTrs by synthesizing oligonucleotides with 2'-5'-phosphodiester bonds de novo.
authors.affiliation: Department of Cell Biology, Biozentrum, University of Basel, Basel, Switzerland.
authors.forename: Georges
authors.initials: G
authors.lastname: Martin
authors.forename: Walter
authors.initials: W
authors.lastname: Keller
mesh_terms: D015088:2',5'-Oligoadenylate Synthetase / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000378:metabolism; D011062:Polynucleotide Adenylyltransferase / Q000737:chemistry / Q000378:metabolism; D012316:RNA Nucleotidyltransferases / Q000737:chemistry / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C440000:A adding enzyme; C439999:CC adding enzyme; D009713:Nucleotidyltransferases; D012316:RNA Nucleotidyltransferases; C031687:UTP-RNA uridylyltransferase; C520554:Cid1 protein, S pombe; D011062:Polynucleotide Adenylyltransferase; D012321:DNA-Directed RNA Polymerases; C506067:Trf5 protein, S cerevisiae; D004259:DNA-Directed DNA Polymerase; C487545:PAP2 protein, S cerevisiae; D015088:2',5'-Oligoadenylate Synthetase