Carbonic anhydrase alpha (vertebrate-like) group. 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 and a fourth conserved histidine plays a potential role in proton transfer.

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gi 160380596  27 QLHLVHWNAVKFENFEDAALEENGLAVIGVFLKI 60
Cdd:cd03118   93 ELHLVHWNSVKYENFEEAVMEENGLAVIGVFLKL 126

Carbonic anhydrase alpha, CA isozyme V_like subgroup. 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. Most alpha CAs are monomeric enzymes. The zinc ion is complexed by three histidines. This vertebrate subgroup comprises isozyme V. CA V is the mitochondrial isozyme, which may play a role in gluconeogenesis and ureagenesis and possibly also in lipogenesis.

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gi 160380596  27 QLHLVHWNAVKFENFEDAALEENGLAVIGVFLKI 60
Cdd:cd03118   93 ELHLVHWNSVKYENFEEAVMEENGLAVIGVFLKL 126

Eukaryotic-type carbonic anhydrase; Carbonic anhydrases are zinc metalloenzymes which catalyse the reversible hydration of carbon dioxide to bicarbonate.. CAs have essential roles in facilitating the transport of carbon dioxide and protons in the intracellular space, across biological membranes and in the layers of the extracellular space; they are also involved in many other processes, from respiration and photosynthesis in eukaryotes to cyanate degradation in prokaryotes. There are five known evolutionarily distinct CA families (alpha, beta, gamma, delta and epsilon) that have no significant sequence identity and have structurally distinct overall folds. Some CAs are membrane-bound, while others act in the cytosol; there are several related proteins that lack enzymatic activity. The active site of alpha-CAs is well described, consisting of a zinc ion coordinated through 3 histidine residues and a water molecule/hydroxide ion that acts as a potent nucleophile. The enzyme employs a two-step mechanism: in the first step, there is a nucleophilic attack of a zinc-bound hydroxide ion on carbon dioxide; in the second step, the active site is regenerated by the ionisation of the zinc-bound water molecule and the removal of a proton from the active site. Beta- and gamma-CAs also employ a zinc hydroxide mechanism, although at least some beta-class enzymes do not have water directly coordinated to the metal ion.

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gi 160380596    28 LHLVHWNAVKfeNFEDAALEENGLAVIGVFLKISET 63
Cdd:smart01057 113 LHLVHYNSKG--SFSEAVSKPGGLAVVAVFFKVGAE 146

Carbonic anhydrase alpha, CA isozyme V_like subgroup. 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. Most alpha CAs are monomeric enzymes. The zinc ion is complexed by three histidines. This vertebrate subgroup comprises isozyme V. CA V is the mitochondrial isozyme, which may play a role in gluconeogenesis and ureagenesis and possibly also in lipogenesis.

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gi 160380596  27 QLHLVHWNAVKFENFEDAALEENGLAVIGVFLKI 60
Cdd:cd03118   93 ELHLVHWNSVKYENFEEAVMEENGLAVIGVFLKL 126

Carbonic anhydrase alpha, CA isozyme VII_like subgroup. 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. Most alpha CAs are monomeric enzymes. The zinc ion is complexed by three histidines. This vertebrate subgroup comprises isozyme VII. CA VII is the most active cytosolic enzyme after CA II, and may be highly expressed in the brain. Human CA VII may be a target of antiepileptic sulfonamides/sulfamates.

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gi 160380596  27 QLHLVHWNAVKFENFEDAALEENGLAVIGVFLKI 60
Cdd:cd03149   93 ELHLVHWNAKKYKSFGEAAAAPDGLAVLGVFLET 126

Carbonic anhydrase alpha (vertebrate-like) group. 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 and a fourth conserved histidine plays a potential role in proton transfer.

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                 ....*....|....*....|....*....|....*..
gi 160380596  28 LHLVHWNAVKFENfeDAALEENGLAVIGVFLKISETS 64
Cdd:cd00326   92 LHLVHYNSDYYSS--EAAKKPGGLAVLGVFFEVGEKE 126

Carbonic anhydrase alpha, isozymes VI, IX, XII and XIV. 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. Alpha CAs are mostly monomeric enzymes. The zinc ion is complexed by three histidine residues. This sub-family comprises the secreted CA VI, which is found in saliva, for example, and the membrane proteins CA IX, XII, and XIV.

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gi 160380596  27 QLHLVHWNAVKFENFEDAALEENGLAVIGVFLKISET 63
Cdd:cd03123  106 ELHIVHYNSDKYSSFDEAADKPDGLAVLAILIEVGYP 142

Carbonic anhydrase alpha related protein, group VIII. Carbonic anhydrase related proteins (CARPs) are sequence similar to carbonic anhydrases. Carbonic anhydrases are zinc-containing enzymes that catalyze the reversible hydration of carbon dioxide in a two-step mechanism. CARPs have lost conserved histidines involved in zinc binding and consequently their catalytic activity. CARP VIII may play roles in various biological processes of the central nervous system, and could be involved in protein-protein interactions. CARP VIII has been shown to bind inositol 1,4,5-triphosphate (IP3) receptor type I (IP3RI), reducing the affinity of the receptor for IP3. IP3RI is an intracellular IP3-gated Ca2+ channel located on intracellular Ca2+ stores. IP3RI converts IP3 signaling into Ca2+ signaling thereby participating in a variety of cell functions.

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gi 160380596  27 QLHLVHWNAVKFENFEDAALEENGLAVIGVFLKI 60
Cdd:cd03120  106 ELHLIHWNSTLYSSLEEAMGKPHGIAIIALFVQI 139