Enzyme superfamily

Enzyme superfamily‏‎

An enzyme superfamily‏‎ is a large group of enzymes that share a common evolutionary origin, as evidenced by their structural and functional similarities. These superfamilies are typically composed of several protein families, each of which includes enzymes that perform a specific type of reaction. Despite their diverse functions, members of an enzyme superfamily share a common catalytic mechanism or a common structural feature that is indicative of a shared evolutionary origin.

Structure and Function

Enzyme superfamilies are characterized by their shared structural features. These features often include a common protein fold, which is a specific arrangement of amino acids in the protein's three-dimensional structure. This common fold is often associated with a specific catalytic mechanism, which is the method by which the enzyme facilitates a chemical reaction.

In addition to their shared structural features, enzyme superfamilies also share functional similarities. These similarities often involve the types of reactions that the enzymes catalyze. For example, members of the serine protease superfamily all catalyze the hydrolysis of peptide bonds, despite their diverse substrate specificities and biological roles.

Evolution

The existence of enzyme superfamilies provides evidence for the evolution of enzymes. It is believed that all members of a superfamily evolved from a common ancestor through a process of gene duplication and subsequent divergent evolution. This process allows for the development of new enzymatic functions while preserving the original function in other copies of the gene.

Examples

There are many examples of enzyme superfamilies, including the serine protease superfamily, the cytochrome P450 superfamily, and the dehydrogenase superfamily. Each of these superfamilies includes a diverse range of enzymes that perform a variety of biological functions, yet share a common structural feature or catalytic mechanism.

See also

• Protein family
• Protein superfamily
• Enzyme family
• Evolution of enzymes