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Native Aminoacyl-tRNA Synthetase/tRNA Pair Drives Highly Efficient Noncanonical Amino Acid Incorporation in Escherichia coli
Site-specific noncanonical amino acid (ncAA) mutagenesis in living cells has traditionally relied on heterologous, nonsense-suppressing aminoacyl-tRNA synthetase (aaRS)/tRNA pairs that do not cross-react with their endogenous counterparts. Such heterologous pairs often perform suboptimally in a fore...
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Published in: | ACS chemical biology 2024-07, Vol.19 (7), p.1563-1569 |
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Main Authors: | , , , |
Format: | Article |
Language: | English |
Citations: | Items that this one cites |
Online Access: | Get full text |
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Summary: | Site-specific noncanonical amino acid (ncAA) mutagenesis in living cells has traditionally relied on heterologous, nonsense-suppressing aminoacyl-tRNA synthetase (aaRS)/tRNA pairs that do not cross-react with their endogenous counterparts. Such heterologous pairs often perform suboptimally in a foreign host cell since they were not evolutionarily optimized to function in the foreign environment. This suboptimal performance restricts the number of ncAAs that can be simultaneously incorporated into a protein. Here, we show that the use of an endogenous aaRS/tRNA pair to drive ncAA incorporation can offer a potential solution to this limitation. To this end, we developed an engineered Escherichia coli strain (ATMY-C321), wherein the endogenous tyrosyl-tRNA synthetase (TyrRS)/tRNA pair has been functionally replaced with an archaeal counterpart, and the release factor 1 has been removed to eliminate competing termination at the UAG nonsense codons. The endogenous TyrRS/tRNACUA Tyr pair exhibits remarkably efficient nonsense suppression in the resulting cell, relative to established orthogonal ncAA-incorporation systems in E. coli, allowing the incorporation of an ncAA at up to 10 contiguous sites in a reporter protein. Our work highlights the limitations of orthogonal translation systems using heterologous aaRS/tRNA pairs and offers a potential alternative involving the use of endogenous pairs. |
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ISSN: | 1554-8929 1554-8937 1554-8937 |
DOI: | 10.1021/acschembio.4c00221 |