A sequence of amino acids in a certain protein is found to be -Ser-Gly-Pro-Gly-. The sequence is most probably part of a(n):
A) antiparallel $\beta$ sheet.
B) parallel $\beta$ sheet.
C) $\alpha$ helix.
D) $\alpha$ sheet.
E) $\beta$ turn.

Question

A sequence of amino acids in a certain protein is found to be -Ser-Gly-Pro-Gly-. The sequence is most probably part of a(n):
A) antiparallel $\beta$ sheet.
B) parallel $\beta$  sheet.
C) $\alpha$ helix.
D) $\alpha$ sheet.
E) $\beta$ turn.

Quizplus · Accepted Answer

The sequence -Ser-Gly-Pro-Gly- is characteristic of a β-turn in proteins. β-turns often contain glycine (due to its flexibility) and proline (which induces a kink due to its rigid cyclic structure), facilitating the sharp turn in the polypeptide chain.

A Sequence of Amino Acids in a Certain Protein Is β\betaβ

A Sequence of Amino Acids in a Certain Protein Is $\beta$