Lipoxygenase, mammalian <p>Lipoxygenases (<db_xref db="EC" dbkey="1.13.11.-"/>) are a class of iron-containing dioxygenases which catalyses the hydroperoxidation of lipids, containing a cis,cis-1,4-pentadiene structure. They are common in plants where they may be involved in a number of diverse aspects of plant physiology including growth and development, pest resistance, and senescence or responses to wounding. In mammals a number of lipoxygenases isozymes are involved in the metabolism of prostaglandins and leukotrienes [<cite idref="PUB00000045"/>]. Sequence data is available for the following lipoxygenases: </p><p> <ul><li>Plant lipoxygenases (<db_xref db="EC" dbkey="1.13.11.12"/>, <db_xref db="INTERPRO" dbkey="IPR001246"/>). Plants express a variety of cytosolic isozymes as well as what seems to be a chloroplast isozyme [<cite idref="PUB00002887"/>].</li><li>Mammalian arachidonate 5-lipoxygenase (<db_xref db="EC" dbkey="1.13.11.34"/>, <db_xref db="INTERPRO" dbkey="IPR001885"/>).</li><li>Mammalian arachidonate 12-lipoxygenase (<db_xref db="EC" dbkey="1.13.11.31"/>, <db_xref db="INTERPRO" dbkey="IPR001885"/>).</li><li>Mammalian erythroid cell-specific 15-lipoxygenase (<db_xref db="EC" dbkey="1.13.11.33"/>, <db_xref db="INTERPRO" dbkey="IPR001885"/>).</li></ul> </p><p>The iron atom in lipoxygenases is bound by four ligands, three of which arehistidine residues [<cite idref="PUB00005162"/>]. Six histidines are conserved in all lipoxygenase sequences, five of them are found clustered in a stretch of 40 amino acids. This region contains two of the three iron-ligands; the other histidines have been shown [<cite idref="PUB00000363"/>] to be important for the activity of lipoxygenases.</p><p>This entry represents mammalian lipoxygenases.</p>