Nucleic Acids Research, 1990, Vol. 18, No. 18 5381-5386
© 1990
MOLECULAR BIOLOGY |
A single mutation in 16S rRNA that affects mRNA binding and translation-termination
Max-Planck-Institut für Molekulare Genetik, Abt. Wittmann, Ihnestrasse 73, 1000 Berlin 33, FRG
*To whom correspondence should be addressed
Received July 9, 1990. Accepted August 29, 1990.
A single base change in 16S rRNA (C726 to G) has previously been shown to have a dramatic effect on protein synthesis in E. coli(1). This paper more specifically details the effects of the mutation on mRNA binding and translation-termination. The in vitrotechnique of toeprinting (2) was used to demonstrate that 30S subunits containing the mutation 726G had an altered binding affinity for mRNA by comparison to the wild type. In addition, expression of the mutant ribosomes in vivo resulted in exclusive suppression of the UGA nonsense codon. This effect was supported by in vitrostudies that showed the mutant ribosomes to have an altered binding affinity for Release Factor-2.