Mutagenesis of the modified bases, m(5)U1939 and psi2504, in Escherichia coli 23S rRNA.
Ribosomal RNAs (rRNAs) from all kingdoms contain a variety of post-transcriptional modifications and these are typically clustered in the functional centers of the ribosome. The functions of two bases in the 23S rRNA of Escherichia coli that are post-transcriptionally modified, m(5)U1939 and psi2504, were examined by mutagenesis of the rRNA bases and by inactivation of the RumA methylase that methylates U1939. Base substitutions at U1939 had little effect on growth or the fidelity of translation, but altered the sensitivity of the ribosomes to the antibiotics fusidic acid and capreomycin. Strains lacking the RumA methylase were gradually out-competed by wild type strains in growth competition experiments, suggesting that the m(5)U methylation improves ribosome performance. Base changes at psi2504 had dramatic effects on growth and resistance to several peptidyltransferase inhibitor antibiotics and increased the levels of translational errors. The results link these sites of post-transcriptional modification with the ribosome's response to antibiotics and the control of translational fidelity.
Persaud
Clive
C
School of Biological Sciences, University of Missouri-Kansas City, 5007 Rockhill Road, Kansas City, MO 64110, USA.
Lu
Ying
Y
Vila-Sanjurjo
Antón
A
Campbell
Jamie L
JL
Finley
Jason
J
O'Connor
Michael
M
D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D008745:Methylation; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D016296:Mutagenesis; D011487:Protein Conformation; D012338:RNA, Ribosomal, 23S / Q000235:genetics / Q000378:metabolism*; D054681:Ribosome Subunits, Large, Bacterial / Q000737:chemistry / Q000378:metabolism; D014529:Uridine / Q000031:analogs & derivatives* / Q000235:genetics / Q000378:metabolism
D012338:RNA, Ribosomal, 23S; C009182:ribothymidine; D008780:Methyltransferases; C547819:RumA protein, E coli; D014529:Uridine