You Have Isolated a Novel Protein, Characterized Its Structure and Determined

Multiple Choice

You have isolated a novel protein, characterized its structure and determined that it catalyzes the breakdown of a large substrate and has two binding sites. One of these is large, apparently the binding site for the large substrate; the other is small, possibly a binding site for a regulatory molecule. What do these findings suggest to you about the mode of action of this protein?

A) It is probably a structural protein that is found in tendons or bone.
B) It is probably an enzyme that is controlled through allosteric regulation.
C) It is probably an enzyme that works through autophosphorylation.
D) It is probably a transmembrane protein-like a G protein-coupled receptor.