Ligase

In biochemistry, a ligase is an enzyme that can catalyse the joining of two molecules ("ligation" or "gluing together") by forming a new chemical bond, with accompanying hydrolysis of ATP or other similar molecules. For example, an enzyme that catalyzed this reaction would be a ligase:

A + B → A–B

Contents

1 Nomenclature 2 Classification 3 See also 4 References

Nomenclature

The common names of ligases often include the word "ligase," such as DNA ligase, an enzyme commonly used in molecular biology laboratories to join together DNA fragments. Other common names include "synthase" or "synthetase" (because they are used to synthesize new molecules), or "carboxylase" (when they are used to add carbon dioxide to a molecule).

Classification

Ligases are classified as EC 6 in the EC number classification of enzymes. Ligases can be further classified into six subclasses:

• EC 6.1 includes ligases used to form carbon-oxygen bonds
• EC 6.2 includes ligases used to form carbon-sulfur bonds
• EC 6.3 includes ligases used to form carbon-nitrogen bonds
• EC 6.4 includes ligases used to form carbon-carbon bonds
• EC 6.5 includes ligases used to form phosphoric ester bonds
• EC 6.6 includes ligases used to form nitrogen-metal bonds

See also

• Hydrolase
• Isomerase
• Lyase
• Oxidoreductase
• Transferase

References

EC 6 Introduction from the Department of Chemistry at Queen Mary University of London

See also: Ligase, Adenosine triphosphate, Biochemistry, Carbon dioxide, Chemical bond, DNA ligase, EC number, Enzyme, Hydrolase, Hydrolysis