Cys-tRNACys (Cys-charged tRNACys) can be converted to Ala-tRNACys (Ala-charged tRNACys) by catalytic reduction. Assume that Ala-tRNACys is added into a functional in vitro translation system that contains all the essential components for translation, including: ribosomes, all tRNAs excluding tRNACys, all amino acids, mRNA encoding for a given protein, and all other essential cofactors / enzymes required for translation. Where in the newly synthesized protein would Ala be incorporated? a. at the positions where Ala and Cys normally occur for this protein.
b. at the positions where Ala normally occurs for this protein.
c. at the positions where Cys normally occurs for this protein.
d. at the positions where Ala-Cys dipeptides normally occur for this protein.
e. ala won't be incorporated, because Ala-TRNACys won't be recognized by the ribosome.