The C-terminal helix of Pseudomonas aeruginosa elongation factor Ts tunes EFT-Tu dynamics to modulate nucleotide exchange
De Laurentiis, Evelina I.
American Society for Biochemistry and Molecular Biology
Little is known about the conservation of critical kinetic parameters and the mechanistic strategies of elongation factor (EF) Ts-catalyzed nucleotide exchange in EF-Tu in bacteria and particularly in clinically relevant pathogens. EF-Tu from the clinically relevant pathogen Pseudomonas aeruginosa shares over 84% sequence identity with the corresponding elongation factor from Escherichia coli. Interestingly, the functionally closely linked EF-Ts only shares 55% sequence identity. To identify any differences in the nucleotide binding properties, as well as in the EF-Ts-mediated nucleotide exchange reaction, we performed a comparative rapid kinetics and mutagenesis analysis of the nucleotide exchange mechanism for both the E. coli and P. aeruginosa systems, identifying helix 13 of EF-Ts as a previously unnoticed regulatory element in the nucleotide exchange mechanism with species-specific elements. Our findings support the base side-first entry of the nucleotide into the binding pocket of the EF-Tu·EF-Ts binary complex, followed by displacement of helix 13 and rapid binding of the phosphate side of the nucleotide, ultimately leading to the release of EF-Ts.
Sherpa Romeo green journal. Permission to archive final published version
GTPase , Molecular dynamics , Pre-steady-state kinetics , Pseudomonas aeruginosa (P. aeruginosa) , Translation elongation factor , Elongation factor Ts , Elongation factor Tu , Catalytic mechanism , Nucleotide binding , Nucleotide exchange
De Laurentiis, E. I., Mercier, E., & Wieden, H.-J. (2016). The C-terminal helix of Pseudomonas aeruginosa elongation factor Ts tunes EF-Tu dynamics to modulate nucleotide exchange. Journal of Biological Chemistry, 291(44), 23136-023148. doi:10.1074/jbc.M116.740381