Naslov
Distinctive mechanisms of amino acid selection in the synthetic and editing sites of tRNA synthetases

Autori
Gruić-Sovulj, Ita

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Advances in molecular interaction analysis / Kraševac, Nada & Anderluh, Gregor - Ljubljana : Department of Molecular biology and Nanobiotechnology, National Institute of Chemistry, 2016, 16-16

ISBN
978-961-6104-32-6

Skup
5th MiniSimpozij 2016 Advances in Molecular Interaction Analysis

Mjesto i datum
Ljubljana, Slovenija, 22.11.2106

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
editing ; aminoacyl-tRNA synthetases ; leucyl-tRNA synthetase ; norvaline

Sažetak
Amino acids are directed into protein synthesis by their coupling to the cognate tRNAs in the reactions catalyzed by corresponding aminoacyl- tRNA synthetases (aaRS). These enzymes may use editing to prevent accumulation of aa-tRNA mismatches. The prominent error-correction step is hydrolysis of misacylated tRNAs within a dedicated protein domain. Also, the near-cognate aminoacyl-adenylate intermediate may be proofread within the synthetic site. Using several class I aaRSs as model enzymes we tackle the mechanisms and evolution of amino acid discrimination and editing. We found that the synthetic and editing sites use distinct mechanisms to strengthen specificity. The synthetic site promotes specificity by enabling a 100-fold difference in the Km values for cognate and near-cognate amino acids. In contrast, the post-transfer editing site exclude the corresponding cognate aminoacyl- tRNA, with 103-fold specificity that arises from decreased rate of deacylation. This challenges a general perception in which the editing domain operates as a steric sieve.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija

POVEZANOST RADA