Protein Domain : Metal-dependent hydrolase HDOD IPR013976

Type	Domain
Description	The HD domain, named after the conserved doublet of predicted catalytic residues, is found in a wide range of bacterial, archaeal and eukaryoticproteins. It defines a superfamily of phosphohydrolases that can catalyze both metal-dependent and -independent phosphomonoesterase and phosphodiesterasereactions for a broad range of substrates [ , ]. The HD-domain proteins appear to be involved in nucleic acid and nucleotidemetabolism, signal transduction and possibly other functions. They are diverse in terms of both domain architecture and phylogenetic distribution; each ofthe completely sequenced genomes encodes more than one version of this domain. The HD domain is composed of a bundle of alpha helices with a 5-helix core. Although all HD domains share key design features, a striking diversity of catalytic centres have been identified, containing nometal, mono-, bi- or trinuclear metal binding sites [ , ].The HD-related output domain (HDOD) is a protein domain of unknown function. Proteins containing the HDOD are widespread in diverse bacteria; it can bepresent as a stand-alone domain, and also associated with other domains, such as response regulatory (RR), GGDEF, andEAL, suggesting a role in regulation and signaling [ , ]. Proteins containing this domain include CdgJ from Vibrio cholerae serotype O1. CdgJ is a phosphodiesterase (PDE) that catalyzes the hydrolysis of cyclic diguanylate (c-di-GMP) [].
Short Name	HDOD