Switching the Post-translational Modification of Translation Elongation Factor EF-P.

Wolfram Volkwein,Marina Parr,Zhenghuan Guo,Elena Mankina,Dmitrij Frishman,Janosch Hennig,Jakub Macošek,Jürgen Lassak,Miriam Pfab,Maximilian Josef Ludwig Johannes Fürst,Pravin Kumar Ankush Jagtap,Ralph Krafczyk,Kirsten Jung

doi:10.3389/fmicb.2019.01148

Abstract

Tripeptides with two consecutive prolines are the shortest and most frequent sequences causing ribosome stalling. The bacterial translation elongation factor P (EF-P) relieves this arrest, allowing protein biosynthesis to continue. A seven amino acids long loop between beta-strands β3/β4 is crucial for EF-P function and modified at its tip by lysylation of lysine or rhamnosylation of arginine. Phylogenetic analyses unveiled an invariant proline in the -2 position of the modification site in EF-Ps that utilize lysine modifications such as Escherichia coli. Bacteria with the arginine modification like Pseudomonas putida on the contrary have selected against it. Focusing on the EF-Ps from these two model organisms we demonstrate the importance of the β3/β4 loop composition for functionalization by chemically distinct modifications. Ultimately, we show that only two amino acid changes in E. coli EF-P are needed for switching the modification strategy from lysylation to rhamnosylation.

Highlights

Protein biosynthesis is a universally conserved three-step process that occurs on ribosomes and provides a platform for tRNA mediated amino acid delivery
Cells co-expressing the cognate interaction partners EarPPpu and EF-PPpu emitted a maximum of 7,000 RLU (Figure 1C)
Having shown that the EF-PEco β3 β4 composition is crucial for rhamnosylation dependent rescue of polyproline arrested ribosomes, we examined the role of the specific loop amino acids on protein function

Summary

Introduction

Protein biosynthesis is a universally conserved three-step process that occurs on ribosomes and provides a platform for tRNA mediated amino acid delivery. During translation elongation aminoacyl-tRNAs bind to the ribosomal A-site and peptide bond formation is mediated by a peptidyl-tRNA located in the P-site. When translating stretches of two or more prolines, ribosomes become arrested

Methods

Results

Conclusion