A Strategy for Creating Organisms Dependent on Noncanonical Amino Acids. Issue 31 (27th June 2017)

• Record Type: Journal Article
• Authors: Xuan, Weimin; Schultz, Peter G.
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 31(2017)
• Page Start: 9170
• Page End: 9173
• Publication Date: 2017-06-27
• Subjects: deacetylation -- live vaccines -- lysine -- noncanonical amino acids -- post-translational modifications; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201703553
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The use of noncanonical amino acids (ncAAs) to control the viability of an organism provides a strategy for the development of conditional "kill switches" for live vaccines or engineered human cells. We report an approach inspired by the posttranslational acetylation/deacetylation of lysine residues, in which a protein encoded by a gene with an in‐frame nonsense codon at an essential lysine can be expressed in its native state only upon genetic incorporation of N ‐ ϵ ‐acetyl‐l ‐Lys (AcK), and subsequent enzymatic deacetylation in the host cell. We applied this strategy to two essential E. coli enzymes: the branched‐chain aminotransferase BCAT and the DNA replication initiator protein DnaA. We also devised a barnase‐based conditional suicide switch to further lower the escape frequency of the host cells. This strategy offers a number of attractive features for controlling host viability, including a single small‐molecule‐based kill switch, low escape frequency, and unaffected protein function. Abstract : There's no escape : A PTM‐inspired strategy for creating organisms dependent on noncanonical amino acids was developed in which a protein encoded by a gene with an in‐frame nonsense codon at an essential lysine can be expressed in its native state only upon genetic incorporation of N ‐ ϵ ‐acetyl‐l ‐Lys (AcK) and subsequent enzymatic deacetylation in the host cell. A barnase‐based conditional suicide switch was also devised to further lower the escape frequency.