Would proper termination of transcription in eukaryotes be more likely to be blocked by a
mutation that inactivated CstF or polyA polymerase? Explain.
Solution
Answer : Mutation in either cstF (cleavage stimulatory factor) or Poly A polymerase is nothing
to do with the termination of transcription. As the functions of these proteins is to bring about the
polyadenylation of 3\' end of the eukaryotic mRNA, they start acting only after the termination
of mRNA synthesis. cstF is the cleavage factor which is recruited by cleavage and
polyadenylation specificity factor clevaes the specific region upstream of the 3\' end of newly
synthesised mRNA to which the poly adenylate residues are added by the enzyme Poly A
polymerase.
mutation that inactivated CstF or polyA polymerase? Explain.
Solution
Answer : Mutation in either cstF (cleavage stimulatory factor) or Poly A polymerase is nothing
to do with the termination of transcription. As the functions of these proteins is to bring about the
polyadenylation of 3\' end of the eukaryotic mRNA, they start acting only after the termination
of mRNA synthesis. cstF is the cleavage factor which is recruited by cleavage and
polyadenylation specificity factor clevaes the specific region upstream of the 3\' end of newly
synthesised mRNA to which the poly adenylate residues are added by the enzyme Poly A
polymerase.
