An enzyme subunit is an individual polypeptide component of an enzyme assembled from multiple protein chains. Subunit composition and interfaces establish the molecular architecture of the complete enzyme, including catalytic and regulatory regions [1]. A subunit can carry an active site, a mobile intermediate-bearing domain, or a binding region that connects other components, and different subunits within one assembly can specialize for distinct catalytic, regulatory, or structural functions [2][3]. Repeated copies of a subunit can also form a symmetric core around which additional catalytic components are organized [4]. Interactions across subunit boundaries position residues, channels, and mobile regions so that the assembled enzyme can coordinate the successive events of its catalytic cycle [5].
Enzyme Production and Characterization·Biotechnology·Biochemistry, Genetics and Molecular Biology·Life Sciences