Question

Indicate whether Ribonuclease A has and explain why it has:

a. Secondary structure

b. Tertiary structure

c. Quaternary structure

Answer 1

Ribonuclease A or RNase A is composed of single polypeptide chain having 124 residues.Out of total 20 native amino acids, this enzyme possesses 19 of them (the only exception is tryptophan). The single polypeptide chain of RNase A is cross-linked with disulfide linkages internally. This provides stability to RNase A.The main feature of RNase A is a long four stranded anti-parallel Beta-sheets along with three short alpha-helices which form the secondary structure ( as beta-sheets and alpha-helices are key features of the secondary structure of the protein).

Therefore Ribonuclease A possesses secondary structure.