Saccharomyces cerevisiae protein phosphorylation and translation accuracy

Protein-protein and protein-rRNA interactions involving ribosomal proteins uS4 and uS5 are thought to maintain the accuracy of protein synthesis by increasing selection of cognate aminoacyl-tRNAs. Selectivity involves a major conformational change—domain closure—that stabilizes aminoacyl-tRNA in the ribosomal acceptor (A) site. This has been thought a constitutive function of the ribosome ensuring consistent accuracy. Recently, the Saccharomyces cerevisiae Ctk1 cyclin-dependent kinase was demonstrated to ensure translational accuracy and Ser238 of uS5 proposed as its target. Surprisingly, Ser238 is outside the uS4-uS5 interface and no obvious mechanism has been proposed to explain its role. We show that the true target of Ctk1 regulation is another uS5 residue, Ser176, which lies in the interface opposite to Arg57 of uS4. Based on site-specific mutagenesis, we propose that phospho-Ser176 forms a salt bridge with Arg57, which should increase selectivity by strengthening the interface. Ge..., This dataset is the result of in vivo analysis of misreading error frequency in the yeast Saccharomyces cerevisiae using a set of misreading error reporter systems developed in our laboratory., , # Protein phosphorylation and translation accuracy

The data consist of the results of in vivo misreading reporter assays. The reporter consists of the Escherichia coli lacZ gene, encoding beta-galactosidase, expressed in the yeast Saccharomyces cerevisiae from an autonomously replicating plasmid. The data come from the Beta-Glo system in which galactosyl-luciferin is cleaved by beta-galactosidase releasing luciferin, which is the substrate for a light-dependent reaction with firefly luciferase. The assay is a one-hour timed reaction of excess galactosyl-luciferin with the beta-galactosidase produced in vivo. The amount of luciferin released is then determined in a timed reaction in the presence of excess luciferase. The relative light units (RLUs) produced in this reaction are proportional to misreading frequency and is quantitated by calculating the ratio of RLU produced using extract of a misreading reporter mutant beta-galactosidase enzyme divided by the RLU produced from a wild-t...