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Publication Abstract from PubMed

We have employed a rapid fluorescence-based screen to assess the polyspecificity of several aminoacyl-tRNA synthetases (aaRSs) against an array of unnatural amino acids. We discovered that a p-cyanophenylalanine specific aminoacyl-tRNA synthetase (pCNF-RS) has high substrate permissivity for unnatural amino acids, while maintaining its ability to discriminate against the 20 canonical amino acids. This orthogonal pCNF-RS, together with its cognate amber nonsense suppressor tRNA, is able to selectively incorporate 18 unnatural amino acids into proteins, including trifluoroketone-, alkynyl-, and halogen-substituted amino acids. In an attempt to improve our understanding of this polyspecificity, the X-ray crystal structure of the aaRS-p-cyanophenylalanine complex was determined. A comparison of this structure with those of other mutant aaRSs showed that both binding site size and other more subtle features control substrate polyspecificity.

An Evolved Aminoacyl-tRNA Synthetase with Atypical Polysubstrate Specificity .,Young DD, Young TS, Jahnz M, Ahmad I, Spraggon G, Schultz PG Biochemistry. 2011 Feb 1. PMID:21280675^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.