Consider the Ramachandran plot a If you had a peptide sequen

Consider the Ramachandran plot.

a) If you had a peptide sequence whose dihedral angels consistently remained in the following ranges (-56°>>-58°) & (-46°>>-48°), what secondary structure would you expect to see?

b) If you had a peptide sequence whose dihedral angels consistently remained in the following ranges (-134°>>-136°) & (138°<<140°), what secondary structure would you expect to see?

c) If you had a peptide sequence whose dihedral angels consistently remained in the following ranges (98°>>100°) & (-59°<<-61°), what secondary structure would you expect to see?

d) What amino acid shows a larger range of possible phi and psi angles than those shown by this plot? Which amino acid shows a smaller range of possible phi and psi angles than those shown by this plot?

Solution

a) Right handed alpha helix is the secondary structure which is expected.

b) Anti parallel beta sheet is the secondary structure which is expected.