For parts a d below state whether or not the bond angles ar

For parts a - d below, state whether or not the bond angles are observed (circle one) for protein secondary structures, and if so, state what kind of secondary structures.

a) = +9 0° Observed/ Not observed; Secondary Structure:

     = - 45°

b) = - 130 ° Observed/ Not observed; Secondary Structure:

     = +130 °

c) = - 60 ° Observed/ Not observed; Secondary Structure:

     = - 50 °

d) = - 90 ° Observed/ Not observed; Secondary Structure:

     = - 150°

Solution

Answer D is correct

Explanation: The average phi and psi values for -helices and -sheets should be clustered around -57°, -47° and -80°, +150° according to the Ramachandran plot.

Secondary structure observed is -sheet