The term "quaternary" with respect to protein structure means
A) a repeating structure stabilized by intrachain hydrogen bonds.
B) the ability to form all four kinds of noncovalent bonds.
C) a multisubunit structure.
D) a linear sequence of four amino acids.
E) None of the answers is correct.

Question

Quizplus · Accepted Answer

The term "quaternary" in the context of protein structure refers to the assembly of multiple polypeptide chains (subunits) into a functional protein complex. This level of structure is beyond the primary (sequence of amino acids), secondary (local folding patterns like alpha-helices and beta-sheets), and tertiary (the overall 3D shape of a single polypeptide chain) structures.

The Term "Quaternary" with Respect to Protein Structure Means