title: Analysis of the functional role of conserved residues in the protein subunit of ribonuclease P from Escherichia coli.
abstract: The processing of precursor tRNAs and some other small cellular RNAs by M1 RNA, the catalytic subunit of Escherichia coli ribonuclease P, is accelerated by C5 protein (the protein cofactor) both in vitro and in vivo. In an effort to understand the mechanism by which the protein cofactor promotes and stabilizes certain conformations of M1 RNA that are most efficient for RNase P catalysis, we have used site-directed mutagenesis to generate mutant derivatives of C5 protein and assessed their ability to promote RNase P catalysis in vivo and in vitro. Our results indicate that certain conserved hydrophobic and basic residues in C5 protein are important for its function and that single amino acid residue changes in C5 protein can alter the substrate specificity of the RNase P holoenzyme.
authors.affiliation: Department of Biology, Yale University, New Haven, CT 06520-8103, USA.
authors.forename: V
authors.initials: V
authors.lastname: Gopalan
authors.forename: A D
authors.initials: AD
authors.lastname: Baxevanis
authors.forename: D
authors.initials: D
authors.lastname: Landsman
authors.forename: S
authors.initials: S
authors.lastname: Altman
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D003067:Coenzymes / Q000378:metabolism; D017124:Conserved Sequence / Q000502:physiology*; D004722:Endoribonucleases / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D017433:Protein Structure, Secondary; D012322:RNA Precursors / Q000737:chemistry / Q000378:metabolism; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D016337:RNA, Catalytic / Q000737:chemistry / Q000378:metabolism*; D012365:RNA, Transfer, Tyr / Q000737:chemistry / Q000378:metabolism; D043262:Ribonuclease P; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D003067:Coenzymes; D029968:Escherichia coli Proteins; D012322:RNA Precursors; D012329:RNA, Bacterial; D016337:RNA, Catalytic; D012365:RNA, Transfer, Tyr; D004722:Endoribonucleases; D043262:Ribonuclease P; C470865:ribonuclease P, E coli