Carbonic anhydrase, CA4/CA15 (IPR041874)

Short name: CA4/CA15

Overlapping homologous superfamilies

Family relationships


Carbonic anhydrases (CAs) are zinc-containing enzymes that catalyze the reversible hydration of carbon dioxide in a two-step mechanism: a nucleophilic attack of a zinc-bound hydroxide ion on carbon dioxide, followed by the regeneration of the active site by ionization of the zinc-bound water molecule and removal of a proton from the active site. They are ubiquitous enzymes involved in fundamental processes like photosynthesis, respiration, pH homeostasis and ion transport. There are three evolutionary distinct groups - alpha, beta and gamma carbonic anhydrases - which show no significant sequence identity or structural similarity. Most alpha CAs are monomeric enzymes. The zinc ion is complexed by three histidine residues [PMID: 11696553, PMID: 9336012].

This subgroup of carbonic anhydrases, restricted to animals, contains isozyme IV and similar proteins such as mouse CA XV. Isozymes IV is attached to membranes via a glycosylphosphatidylinositol (GPI) tail. In mammals, Isozyme IV plays crucial roles in kidney and lung function, among others [PMID: 24146379]. This subgroup also contains the dual domain CA from the giant clam, Tridacna gigas. T. gigas CA plays a role in the movement of inorganic carbon from the surrounding seawater to the symbiotic algae found in the clam's tissues [PMID: 15978036]. CA XV is expressed in several species but not in humans or chimps. Similar to isozyme CA IV, CA XV attaches to membranes via a GPI tail [PMID: 16083424].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0004089 carbonate dehydratase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.