Plasticity and Constraints of tRNA Aminoacylation Define Directed Evolution of Aminoacyl-tRNA Synthetases

International Journal of Molecular Sciences

Dieter Söll¹  Oscar Vargas-Rodriguez¹  Ana Crnković¹ 

[1] Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA;

关键词: aminoacyl-tRNA synthetases;    noncanonical amino acids;    directed evolution;    genetic code expansion;    synthetic biology;   

DOI  :  10.3390/ijms20092294

来源: DOAJ

【 摘 要 】

Genetic incorporation of noncanonical amino acids (ncAAs) has become a powerful tool to enhance existing functions or introduce new ones into proteins through expanded chemistry. This technology relies on the process of nonsense suppression, which is made possible by directing aminoacyl-tRNA synthetases (aaRSs) to attach an ncAA onto a cognate suppressor tRNA. However, different mechanisms govern aaRS specificity toward its natural amino acid (AA) substrate and hinder the engineering of aaRSs for applications beyond the incorporation of a single l-α-AA. Directed evolution of aaRSs therefore faces two interlinked challenges: the removal of the affinity for cognate AA and improvement of ncAA acylation. Here we review aspects of AA recognition that directly influence the feasibility and success of aaRS engineering toward d- and β-AAs incorporation into proteins in vivo. Emerging directed evolution methods are described and evaluated on the basis of aaRS active site plasticity and its inherent constraints.

【 授权许可】

Unknown