Site-Specific Incorporation of Fluorotyrosines into Proteins in Escherichia coli by Photochemical Disguise

Fluorinated analogues of tyrosine call be used to Manipulate the electronic environments of protein active sites. The ability to selectively Mutate tyrosine residues to fluorotyrosines is limited, however, and call Currently only be achieved through the total synthesis of proteins. As it general Solution to this problem, we genetically encoded the unnatural amino acids o-nitrobenzyl-2-fluorotyrosine, -3-fluorotyrosine, and -2,6-difluorotyrosine in Escherichia coli. These amino acids are disguised from recognition by the endogenous protein biosynthetic machinery, effectively preventing global incorporation of fluorotyrosine into proteins.