<p>This domain is found in diverse bacterial signalling proteins. It is called EAL after its conserved residues. The EAL domain is a good candidate for a diguanylate phosphodiesterase function [<cite idref="PUB00007150"/>]. The domain contains many conserved acidic residues that could participate in metal binding and might form the phosphodiesterase active site. It often but not always occurs along with <db_xref db="INTERPRO" dbkey="IPR000014"/> and <db_xref db="INTERPRO" dbkey="IPR000160"/> domains that are also found in many signalling proteins.</p>