
PyC as a fluorescence probe in E. coli tRNACys. (A) The chemical structure of PyCTP used for incorporation by Bst CCA-adding enzyme. Inward and outward arrows denote hydrogen bond acceptors and donors, respectively. (B) A scheme showing the cloverleaf of E. coli tRNACys-C74 as the substrate for Bst CCA enzyme for incorporation of PyC75 and A76, using PyCTP and ATP as the substrates.










