<p>This domain is found in plant proteins such as respiratory burst NADPH oxidase proteins which produce reactive oxygen species as a defence mechanism. It tends to occur to the N terminus of an EF-hand (<db_xref db="INTERPRO" dbkey="IPR002048"/>), which suggests a direct regulatory effect of Ca2+ on the activity of the NADPH oxidase in plants [<cite idref="PUB00020945"/>]. </p> NADPH oxidase Respiratory burst