title: Archaeal-bacterial chimeric RNase P RNAs: towards understanding RNA's architecture, function and evolution.
abstract: The higher protein content of archaeal RNase P (1 RNA+4 proteins) compared to the bacterial homologue (1 RNA+1 protein) correlates with a large loss of RNA-alone activity (i.e., in the absence of protein cofactors). Here we show, for the first time, that a catalytic (C) domain of an archaeal RNase P RNA (P RNA) can functionally replace the Escherichia coli C domain in a chimeric P RNA, to provide the essential RNase P function in E. coli cells. This adaptation was achieved by 1) three minor alterations in the archaeal C domain, 2) restoration of the L9-P1 interdomain contact that is found in bacterial and archaeal type A RNAs, and 3) installation of another interdomain contact (L18-P8) that is present in bacterial but absent in archaeal P RNAs. We conclude 1) that the C domains of bacterial and archaeal P RNAs of type A have been largely conserved since the evolutionary separation of bacteria and archaea, and 2) that the L18-P8 RNA-RNA contact has been replaced with protein-protein contacts in archaeal RNase P. Function of the chimeric P RNA in E. coli required overexpression of the E. coli RNase P protein to increase the RNA's reduced cellular levels; this was attributed to enhanced degradation of the chimeric P RNA.
authors.affiliation: Institut für Biochemie, Justus-Liebig-Universität Giessen, Giessen, Germany.
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Markus
authors.initials: M
authors.lastname: Gössringer
authors.forename: Roland K
authors.initials: RK
authors.lastname: Hartmann
mesh_terms: D001105:Archaea / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D001483:Base Sequence; D004926:Escherichia coli / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D050506:Mutant Chimeric Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009690:Nucleic Acid Conformation; D017434:Protein Structure, Tertiary; D019642:RNA, Archaeal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D043262:Ribonuclease P / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016963:Thermus thermophilus / Q000737:chemistry / Q000201:enzymology / Q000235:genetics
chemical_list: D050506:Mutant Chimeric Proteins; D019642:RNA, Archaeal; D012329:RNA, Bacterial; D043262:Ribonuclease P