Principles of Biochemistry

5.2.1.3 Tertiary structure

The tertiary structure of a protein refers to the three dimensional shape of the polypeptide including its side chains. It is caused by weak interactions among side chain groups and between side chain group and the fluid environment. The secondary structures of large proteins often are organized as domains compact units connected by the polypeptide backbone. Folding of the polypeptide within one domain usually occurs independently of folding in other domains.

 

Tertiary structure describes the relationship of these domains, the way in which protein folding and bring together amino acids far apart in a primary structural sense, and the bonds that stabilize these conformations.

                     Tertiary structure: One complete protein chain