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Publication Abstract from PubMed

The absence of orthogonal aminoacyl-transfer RNA (tRNA) synthetases that accept non-L-alpha-amino acids is a primary bottleneck hindering the in vivo translation of sequence-defined hetero-oligomers and biomaterials. Here we report that pyrrolysyl-tRNA synthetase (PylRS) and certain PylRS variants accept alpha-hydroxy, alpha-thio and N-formyl-L-alpha-amino acids, as well as alpha-carboxy acid monomers that are precursors to polyketide natural products. These monomers are accommodated and accepted by the translation apparatus in vitro; those with reactive nucleophiles are incorporated into proteins in vivo. High-resolution structural analysis of the complex formed between one PylRS enzyme and a m-substituted 2-benzylmalonic acid derivative revealed an active site that discriminates prochiral carboxylates and accommodates the large size and distinct electrostatics of an alpha-carboxy substituent. This work emphasizes the potential of PylRS-derived enzymes for acylating tRNA with monomers whose alpha-substituent diverges substantially from the alpha-amine of proteinogenic amino acids. These enzymes or derivatives thereof could synergize with natural or evolved ribosomes and/or translation factors to generate diverse sequence-defined non-protein heteropolymers.

Expanding the substrate scope of pyrrolysyl-transfer RNA synthetase enzymes to include non-alpha-amino acids in vitro and in vivo.,Fricke R, Swenson CV, Roe LT, Hamlish NX, Shah B, Zhang Z, Ficaretta E, Ad O, Smaga S, Gee CL, Chatterjee A, Schepartz A Nat Chem. 2023 Jun 1. doi: 10.1038/s41557-023-01224-y. PMID:37264106^[1]

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