title: The RNase P RNA from cyanobacteria: short tandemly repeated repetitive (STRR) sequences are present within the RNase P RNA gene in heterocyst-forming cyanobacteria.
abstract: The RNase P RNA gene (rnpB) from 10 cyanobacteria has been characterized. These new RNAs, together with the previously available ones, provide a comprehensive data set of RNase P RNA from diverse cyanobacterial lineages. All heterocystous cyanobacteria, but none of the non-heterocystous strains analyzed, contain short tandemly repeated repetitive (STRR) sequences that increase the length of helix P12. Site-directed mutagenesis experiments indicate that the STRR sequences are not required for catalytic activity in vitro. STRR sequences seem to have recently and independently invaded the RNase P RNA genes in heterocyst-forming cyanobacteria because closely related strains contain unrelated STRR sequences. Most cyanobacteria RNase P RNAs lack the sequence GGU in the loop connecting helices P15 and P16 that has been established to interact with the 3'-end CCA in precursor tRNA substrates in other bacteria. This character is shared with plastid RNase P RNA. Helix P6 is longer than usual in most cyanobacteria as well as in plastid RNase P RNA.
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Isla de la Cartuja, Universidad de Sevilla-CSIC, Avenida Americo Vespucio s/n, 41092 Sevilla, Spain. vioque@cica.es
authors.forename: A
authors.initials: A
authors.lastname: Vioque
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D000458:Cyanobacteria / Q000201:enzymology / Q000235:genetics*; D004722:Endoribonucleases / Q000235:genetics*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D012329:RNA, Bacterial / Q000737:chemistry*; D016337:RNA, Catalytic / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D043262:Ribonuclease P
chemical_list: D012329:RNA, Bacterial; D016337:RNA, Catalytic; D004722:Endoribonucleases; D043262:Ribonuclease P