
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.
Item Type: | Journal article |
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Faculties: | Biology > Department Biology I |
Subjects: | 500 Science > 570 Life sciences; biology |
URN: | urn:nbn:de:bvb:19-epub-33392-1 |
ISSN: | 2211-1247 |
Language: | English |
Item ID: | 33392 |
Date Deposited: | 15. Feb 2017, 14:44 |
Last Modified: | 04. Nov 2020, 13:11 |