Ligase
In
In general, a ligase catalyzes the following dehydration reaction, thus joining molecules A and B:
A-OH + B-H → A–B + H2O
Nomenclature
The naming of ligases is inconsistent and so these enzymes are commonly known by several different names. Generally, the common names of ligases include the word "ligase", such as in DNA ligase, an enzyme commonly used in molecular biology laboratories to join together DNA fragments. However, many common names use the term "synthetase" or "synthase" instead, because they are used to synthesize new molecules.[1] There are also some ligases that use the name "carboxylase" to indicate that the enzyme specifically catalyzes a carboxylation reaction.
To note: biochemical nomenclature has sometimes distinguished synthetases from synthases and sometimes treated the words as synonyms.[2] Commonly, the two terms are used interchangeably and are both used to describe ligases.
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
- argininosuccinate synthetase)
- EC 6.4 includes ligases used to form carbon-carbon bonds, such as acetyl-CoA carboxylase
- phosphoric ester bonds, such as DNA ligase
- EC 6.6 includes ligases used to form nitrogen-metal bonds, as in the chelatases
Membrane-associated ligases
Some ligases associate with
Etymology and pronunciation
The word ligase uses
See also
References
- ^ "IntEnz - EC 6". www.ebi.ac.uk. Retrieved May 2, 2023.
- ^ "Synthetases - Ligases - Enzymes - Products". www.axonmedchem.com. Retrieved May 2, 2023.
- ^ Superfamilies of single-pass transmembrane ligases in Membranome database
- EC 6 Introduction from the Department of Chemistry at Queen Mary, University of London