A section of a protein chain is as follows:
-N-Pro-X-Val-N-
What is X, given the following dihedral angles (starting at proline and moving right)?
φ1 is +60º, φ2 is 180º, ψ1 is -60º, ψ2 is 0º, ω1 is 0º, ω2 is 180º