title: A structural and functional study of plastid RNAs homologous to catalytic bacterial RNase P RNA.
abstract: Ribonuclease P (RNase P), the ubiquitous enzyme required for 5' maturation of transfer RNA, is a ribonucleoprotein containing an essential RNA subunit. This RNA (P RNA) is the catalytic component of RNase P in Bacteria and some Archaea. A putative P RNA is encoded in the chloroplast genome of three algae: Cyanophora paradoxa, Porphyra purpurea and Nephroselmis olivacea. In no case, the P RNAs from the plastids were active in vitro in conditions where bacterial and some archaeal P RNAs are functional. By using lead-ion-induced hydrolysis, we conclude that the catalytic deficiency is most likely due to the perturbation of the global structure of the plastid P RNAs compared to the bacterial counterpart. As a consequence, the plastid P RNAs are unable to bind to the precursor tRNA substrates. We discuss these results in the context of plastid and RNase P evolution.
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Centro de Investigaciones Científicas Isla de la Cartuja, Avda. Américo Vespucio s/n, Sevilla E-41092, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: de la Cruz
authors.forename: Agustín
authors.initials: A
authors.lastname: Vioque
mesh_terms: D001483:Base Sequence; D000460:Chlorophyta / Q000235:genetics; D044424:Cyanophora / Q000235:genetics; D018742:DNA, Chloroplast / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D056890:Eukaryota / Q000235:genetics*; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D044664:Porphyra / Q000235:genetics; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016337:RNA, Catalytic / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018747:RNA, Chloroplast / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D043262:Ribonuclease P / Q000235:genetics* / Q000378:metabolism
chemical_list: D018742:DNA, Chloroplast; D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D016337:RNA, Catalytic; D018747:RNA, Chloroplast; D043262:Ribonuclease P; C470865:ribonuclease P, E coli