RRC ID 35533
著者 Ohtake K, Sato A, Mukai T, Hino N, Yokoyama S, Sakamoto K.
タイトル Efficient decoding of the UAG triplet as a full-fledged sense codon enhances the growth of a prfA-deficient strain of Escherichia coli.
ジャーナル J Bacteriol
Abstract We previously reassigned the amber UAG stop triplet as a sense codon in Escherichia coli by expressing a UAG-decoding tRNA and knocking out the prfA gene, encoding release factor 1. UAG triplets were left at the ends of about 300 genes in the genome. In the present study, we showed that the detrimental effect of UAG reassignment could be alleviated by increasing the efficiency of UAG translation instead of reducing the number of UAGs in the genome. We isolated an amber suppressor tRNA(Gln) variant displaying enhanced suppression activity, and we introduced it into the prfA knockout strain, RFzero-q, in place of the original suppressor tRNA(Gln). The resulting strain, RFzero-q3, translated UAG to glutamine almost as efficiently as the glutamine codons, and it proliferated faster than the parent RFzero-q strain. We identified two major factors in this growth enhancement. First, the sucB gene, which is involved in energy regeneration and has two successive UAG triplets at the end, was expressed at a higher level in RFzero-q3 than RFzero-q. Second, the ribosome stalling that occurred at UAG in RFzero-q was resolved in RFzero-q3. The results revealed the importance of "backup" stop triplets, UAA or UGA downstream of UAG, to avoid the deleterious impact of UAG reassignment on the proteome.
巻・号 194(10)
ページ 2606-13
公開日 2012-5-1
DOI 10.1128/JB.00195-12
PII JB.00195-12
PMID 22427623
PMC PMC3347192
MeSH Cell Proliferation Chromosomes, Bacterial Escherichia coli / genetics Escherichia coli / metabolism* Escherichia coli Proteins / genetics Escherichia coli Proteins / metabolism* Gene Expression Regulation, Bacterial / physiology Genetic Engineering Genome, Bacterial Mutation Peptide Termination Factors / genetics Peptide Termination Factors / metabolism* RNA, Bacterial RNA, Transfer
IF 3.006
引用数 30
WOS 分野 MICROBIOLOGY
リソース情報
原核生物(大腸菌)