G proteins are central to many processes in the cell, including protein synthesis. The G-protein EF-Tu assumes multiple biologically relevant conformations regulated by the binding of guanosine nucleotides. When EF-Tu is bound to GTP it favors a compact structure with domain 1 maintaining close proximity to domains 2 and 3 (see RCSB accession code 1TTT and 1OB2). The tertiary fold achieved by EF-Tu upon GTP binding results in nanomolar affinity for aminoacyl-tRNA. Upon binding, the EF-TuGTPaa-tRNA ternary complex is then a competent substrate for the ribosome.
When bound to GDP, EF-Tu favors an open conformation and has a weak affinity for aa-tRNA (1DG1). The role of exchanging GDP for GTP rest with the guanosine nucleotide exchange factor EF-Ts. We are interested in the role played by EF-Tu and EF-Ts in the fidelity of protein synthesis. We employ a variety of fluorescence based techniques aimed at probing the function and dynamics of these proteins and how antibiotics perturb these properties.
Direct evidence of an elongation factor-Tu/Ts·GTP·Aminoacyl-tRNA quaternary complex. Burnett BJ, Altman RB, Ferguson A, Wasserman MR, Zhou Z, Blanchard SC. J BIOL CHEM (2014) 289(34):23917-23927.
Elongation factor Ts directly facilitates the formation and disassembly of the Escherichia coli elongation factor TuGTPaminoacyl-tRNA ternary complex. Burnett BJ, Altman RB, Ferrao R, Alejo JL, Kaur N, Kanji J, Blanchard SC, J BIOL CHEM (2013), 288(19):13917-13928.