Site-specific mutagenesis of Escherichia coli gltT yields a weak, glutamic acid-inserting ochre suppressor |
| |
Authors: | L A Raftery M Yarus |
| |
Institution: | Department of Molecular, Cellular and Developmental Biology University of Colorado Boulder, Col. 80309, U.S.A. |
| |
Abstract: | Of all the Escherichia coli tRNA genes that can give rise to an amber or an ochre suppressor by a single-nucleotide mutation, only the tRNAGlu genes have not been observed to do so. A study of the relationship between the sequences of tRNAs and the codons they translate predicts that the ochre suppressor derived from tRNAGlu would function very poorly on the ribosome. We have used site-specific mutagenesis to create the gene for such a tRNA in order to test this prediction. We cloned the tRNAGlu-Suoc gene into a high copy number plasmid, under control of the lacUV5 promoter. The mutant tRNA suppresses both amber and ochre nonsense mutations. As predicted, it is less efficient than other suppressors expressed under similar conditions. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|