Here is the cartoon representation and Ramachandran plot of a small DNA-binding protein, 80- residues in length. In its Ramachandran plot, 58 residues fall in the region; 20 residues fall in the region; 2 residues fall in the L region. No residues fall in the disallowed region. The polypeptide termini are labelled. 13. What percentage of the protein is regular structure? A. 3% B. 42% C. 58% D. 97% 14. What percentage of the protein is irregular structure? A. 0% B. 42% C. 75% D. 97% 15. How many domains are present? A. 1 B. 2 C. 3 D. 4 16. How many subunits are present? A. 1 B. 2 C. 3 D. 4 Correct answers: 13) C, 14) B, 15)B, 16) B Please give explanations.