A Conserved Proline Triplet in Val-tRNA Synthetase and the Origin of Elongation Factor P

Starosta, Agata L.; Lassak, Jürgen; Peil, Lauri; Atkinson, Gemma C.; Woolstenhulme, Christopher J.; Virumäe, Kai; Buskirk, Allen; Tenson, Tanel; Remme, Jaanus; Jung, Kirsten und Wilson, Daniel N. (2014): A Conserved Proline Triplet in Val-tRNA Synthetase and the Origin of Elongation Factor P. In: Cell Reports, Bd. 9, Nr. 2: S. 476-483

Abstract

Bacterial ribosomes stall on polyproline stretches and require the elongation factor P (EF-P) to relieve the arrest. Yet it remains unclear why evolution has favored the development of EF-P rather than selecting against the occurrence of polyproline stretches in proteins. We have discovered that only a single polyproline stretch is invariant across all domains of life, namely a proline triplet in ValS, the tRNA synthetase, that charges tRNA(Val) with valine. Here, we show that expression of ValS in vivo and in vitro requires EF-P and demonstrate that the proline triplet located in the active site of ValS is important for efficient charging of tRNA(Val) with valine and preventing formation of mischarged Thr-tRNA(Val) as well as efficient growth of E. coli in vivo. We suggest that the critical role of the proline triplet for ValS activity may explain why bacterial cells coevolved the EF-P rescue system.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Biologie > Department Biologie I
• Themengebiete: 500 Naturwissenschaften und Mathematik > 570 Biowissenschaften; Biologie
• ISSN: 2211-1247
• Sprache: Englisch