key term - Quaternary structure

Definition

The quaternary structure of a protein describes the arrangement and interaction of multiple polypeptide chains (subunits) in a multi-subunit complex. It is the highest level of protein structure, determining the overall 3D arrangement of subunits that are individually folded into their tertiary structures.

Related terms

Primary Structure:

It is the unique sequence of amino acids in a polypeptide chain, determined by genetic information.

Secondary Structure:

This refers to local folded structures that form within a polypeptide due to hydrogen bonding between backbone atoms, commonly α-helices and β-sheets.

Tertiary Structure:

It describes the three-dimensional folding pattern of a single polypeptide chain, including all its bends, folds, and twists into a unique shape