Effects of C5 protein on Escherichia coli RNase P catalysis with a precursor tRNA(Phe) bearing a single mismatch in the acceptor stem.
Escherichia coli RNase P, an RNA-processing enzyme that cleaves precursor tRNAs to generate the mature 5'-end, is composed of a catalytic component (M1 RNA) and a protein cofactor (C5 protein). In this study, effects of C5 protein on the RNase P catalysis with a precursor E. coli tRNA(Phe) having a single mismatch in the acceptor stem were examined. This mutant precursor unexpectedly generated upstream cleavage products at the -8 position as well as normal cleavage products at the +1 position. The cleavage at the -8 position was essentially effective only in the presence of C5 protein. Possible secondary structures for cleavage at the -8 position deviate significantly from the structures of the known RNase P substrates, implying that C5 protein can allow the enzyme to broaden the substrate specificity more than previously appreciated.
Park
B H
BH
Department of Chemistry, Center for Molecular Design and Synthesis, Korea Advanced Institute of Science and Technology, Taejon, 305-701, Korea.
Lee
J H
JH
Kim
M
M
Lee
Y
Y
D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D002384:Catalysis; D017931:DNA Primers / Q000235:genetics; D004722:Endoribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism*; D029968:Escherichia coli Proteins; D007700:Kinetics; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D012322:RNA Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D016337:RNA, Catalytic / Q000378:metabolism*; D012360:RNA, Transfer, Phe / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D043262:Ribonuclease P; D013379:Substrate Specificity
D001426:Bacterial Proteins; D017931:DNA Primers; D029968:Escherichia coli Proteins; D012322:RNA Precursors; D016337:RNA, Catalytic; D012360:RNA, Transfer, Phe; D004722:Endoribonucleases; D043262:Ribonuclease P; C470865:ribonuclease P, E coli