Skip to main page content
U.S. flag

An official website of the United States government

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1995 Dec 19;92(26):12309-13.
doi: 10.1073/pnas.92.26.12309.

UGA suppression by a mutant RNA of the large ribosomal subunit

D K Jemiolo  1 , F T Pagel, E J Murgola
Affiliations

UGA suppression by a mutant RNA of the large ribosomal subunit

D K Jemiolo et al. Proc Natl Acad Sci U S A. .

Abstract

A role for rRNA in peptide chain termination was indicated several years ago by isolation of a 168 rRNA (small subunit) mutant of Escherichia coli that suppressed UGA mutations. In this paper, we describe another interesting rRNA mutant, selected as a translational suppressor of the chain-terminating mutant trpA (UGA211) of E. coli. The finding that it suppresses UGA at two positions in trpA and does not suppress the other two termination codons, UAA and UAG, at the same codon positions (or several missense mutations, including UGG, available at one of the two positions) suggests a defect in UGA-specific termination. The suppressor mutation was mapped by plasmid fragment exchanges and in vivo suppression to domain II of the 23S rRNA gene of the rrnB operon. Sequence analysis revealed a single base change of G to A at residue 1093, an almost universally conserved base in a highly conserved region known to have specific interactions with ribosomal proteins, elongation factor G, tRNA in the A-site, and the peptidyltransferase region of 23S rRNA. Several avenues of action of the suppressor mutation are suggested, including altered interactions with release factors, ribosomal protein L11, or 16S rRNA. Regardless of the mechanism, the results indicate that a particular residue in 23S rRNA affects peptide chain termination, specifically in decoding of the UGA termination codon.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Proc Natl Acad Sci U S A. 1974 Jan;71(1):89-92 - PubMed
    1. Biochim Biophys Acta. 1990 Aug 27;1050(1-3):259-62 - PubMed
    1. Biochemistry. 1991 Feb 19;30(7):1788-95 - PubMed
    1. Nucleic Acids Res. 1991 Aug 11;19(15):4259-65 - PubMed
    1. Annu Rev Biochem. 1991;60:191-227 - PubMed

Publication types

LinkOut - more resources