Quaternary structure refers to the further stabilization of the protein molecule by bonding with one or more similar tertiary structures via further non-covalent interactions and disulfide bonding.

Why do proteins form quaternary structure?

Proteins are long chains of amino acids that fold into complex 3-dimensional shapes. ... This shape is directly related to the function of the protein. Quaternary Structure exists when more than one amino acid chain comes together to form a protein complex.

Why does a protein lack a quaternary structure?

Explanation: Quaternary structure of a protein involves the assembly of subunits. Hemoglobin, p53 and DNA polymerase are all composed of subunits, while myoglobin is a functional single sequence. Since myoglobin does not have multiple subunits, it does not have quaternary structure.