Chapter 27, Problem 17P

Summary Introduction

To explain: The reason why it is impractical to proofread the step that hydrolyzed peptide bond formed previously after the insertion of incorrect amino acid.

Introduction:

The proofreading mechanisms used during replication and protein synthesis are different. DNA (deoxyribonucleic acid) polymerase use $3^{\prime }\to 5^{\prime }$ exonuclease activity to remove mispaired nucleotides. However, there is no such analogous proofreading function on ribosomes. Proofreading translation after the incorporation of amino acid into growing peptide would be impractical.