Labeled EF-Tus for rapid kinetic studies of pretranslocation complex formation

The universally conserved translation elongation factor EF-Tu delivers aminoacyl(aa)-tRNA in the form of an aa-tRNA·EF-Tu·GTP ternary complex (TC) to the ribosome where it binds to the cognate mRNA codon within the ribosomal A-site, leading to formation of a pretranslocation (PRE) complex. Here we describe preparation of QSY9 and Cy5 derivatives of the variant E348C-EF-Tu that are functional in translation elongation. Together with fluorophore derivatives of aa-tRNA and of ribosomal protein L11, located within the GTPase associated center (GAC), these labeled EF-Tus allow development of two new FRET assays that permit the dynamics of distance changes between EF-Tu and both L11 (Tu-L11 assay) and aa-tRNA (Tu-tRNA assay) to be determined during the decoding process. We use these assays to examine: (i) the relative rates of EF-Tu movement away from the GAC and from aa-tRNA during decoding, (ii) the effects of the misreading-inducing antibiotics streptomycin and paromomycin on tRNA selection at the A-site, and (iii) how strengthening the binding of aa-tRNA to EF-Tu affects the rate of EF-Tu movement away from L11 on the ribosome. These FRET assays have the potential to be adapted for high throughput screening of ribosomal antibiotics.

The role of intuition in the translation process:A case study

This paper explores the psychological construct of intuition and its influence in decision-making behavior. Intuition was defined by Jung (1971) as a primary mode of perception operating subconsciously. As opposed to sensing personality types who prefer concrete details, intuitive personality types prefer to acquire information by imagining possibilities (Myers and Myers 1995). In this paper, an analysis of verbalization data from a translation process study is discussed in order to demonstrate the influence of intuition on decision-making during the translation process and to explore the implications of this influence. Recent studies have found that intuition plays a role in learning and decision-making tasks involving affect (Laborde et al. 2010: 786). Intuition is therefore here viewed as a potentially vital component of translator behavior which could predict individuals' translating effectiveness. © John Benjamins Publishing Company.