Posted: July 25th, 2017

It is possible to convert the Cys that is a part of Cys-tRNACys to Ala by a catalytic reduction. If the resulting Ala-tRNACys were added to a mixture of ribosomes, all the other tRNAs and amino acids, all of the cofactors and enzymes needed to make protein in vitro, and mRNA for hemoglobin, where in the newly synthesized hemoglobin would the Ala from Ala-tRNACys be incorporated?

It is possible to convert the Cys that is a part of Cys-tRNACys to Ala
by a catalytic reduction. If the resulting Ala-tRNACys were added to a
mixture of ribosomes, all the other tRNAs and amino acids, all of the
cofactors and enzymes needed to make protein in vitro, and mRNA for
hemoglobin, where in the newly synthesized hemoglobin would the Ala
from Ala-tRNACys be incorporated?
A. wherever Ala normally occurs
B. wherever Cys normally occurs
C. wherever either Ala or Cys normally occurs
D. wherever the dipeptide Ala-Cys normally occurs
E. nowhere; this is the equivalent of a nonsense mutation