Structure and Function of an Elongation Factor P Subfamily in Actinobacteria
Bruno Pinheiro, Christopher M. Scheidler, Pavel Kielkowski, M. Schmid, Ignasi Forné, Suhui Ye, Norbert Reiling, Eriko Takano, Axel Imhof, Stephan A. Sieber, Sabine Schneider, Kirsten Jung
Abstract
Translation of consecutive proline motifs causes ribosome stalling and requires rescue via the action of a specific translation elongation factor, EF-P in bacteria and archaeal/eukaryotic a/eIF5A. In Eukarya, Archaea, and all bacteria investigated so far, the functionality of this translation elongation factor depends on specific and rather unusual post-translational modifications. The phylum Actinobacteria, which includes the genera Corynebacterium, Mycobacterium, and Streptomyces, is of both medical and economic significance. Here, we report that EF-P is required in these bacteria in particular for the translation of proteins involved in amino acid and secondary metabolite production. Notably, EF-P of Actinobacteria species does not need any post-translational modification for activation. While the function and overall 3D structure of this EF-P type is conserved, the loop containing the conserved lysine is flanked by two essential prolines that rigidify it. Actinobacteria's EF-P represents a unique subfamily that works without any modification.