Aldehyde dehydrogenase domain <p>Aldehyde dehydrogenases (<db_xref db="EC" dbkey="1.2.1.3"/> and <db_xref db="EC" dbkey="1.2.1.5"/>) are enzymes that oxidize a wide variety of aliphatic and aromatic aldehydes using NADP as a cofactor. In mammals at least four different forms of the enzyme are known [<cite idref="PUB00000303"/>]: class-1 (or Ald C) a tetrameric cytosolic enzyme, class-2 (or Ald M) a tetrameric mitochondrial enzyme, class- 3 (or Ald D) a dimeric cytosolic enzyme, and class IV a microsomal enzyme. Aldehyde dehydrogenases have also been sequenced from fungal and bacterial species. A number of enzymes are known to be evolutionary related to aldehyde dehydrogenases. A glutamic acid and a cysteine residue have been implicated in the catalytic activity of mammalian aldehyde dehydrogenase. These residues are conserved in all the enzymes of this entry.</p><p>Some of the proteins in this entry are allergens. Allergies are hypersensitivity reactions of the immune system to specific substances called allergens (such as pollen, stings, drugs, or food) that, in most people, result in no symptoms. A nomenclature system has been established for antigens (allergens) that cause IgE-mediated atopic allergies in humans [WHO/IUIS Allergen Nomenclature Subcommittee King T.P., Hoffmann D., Loewenstein H., Marsh D.G., Platts-Mills T.A.E., Thomas W. Bull. World Health Organ. 72:797-806(1994)]. This nomenclature system is defined by a designation that is composed ofthe first three letters of the genus; a space; the first letter of thespecies name; a space and an arabic number. In the event that two speciesnames have identical designations, they are discriminated from one anotherby adding one or more letters (as necessary) to each species designation.</p><p> The allergens in this family include allergens with the following designations: Alt a 10 and Cla h 3.</p>