The GGDEF domain, which has been named after the conserved central sequence pattern GG[DE][DE]F is widespread in prokaryotes. It is typically present in multidomain proteins containing regulatory domains of signaling pathways or protein-protein or protein-ligand interaction modules, such as the response regulatory domain (see <PDOC50110)), the EAL domain (see <PDOC50883>), the PAS/PAC domain (see <PDOC50112>), the HAMP domain (see <PDOC50885>), the GAF domain, the FHA domain (see <PS50006>) or the TPR repeat. However a few single-domain proteins are also known. The GGDEF domain is involved in signal transduction and is likely to catalyze synthesis or hydrolysis of cyclic diguanylate (c-diGMP, bis(3',5')-cyclic diguanylic acid), an effector molecule that consists of two cGMP moieties bound head-to-tail [1,2,3].

Some proteins known to contain a GGDEF domain are listed below:

• Acetobacter xylinus diguanylate cyclases (DGCs) and c-di-GMP phosphodiesterases A (PDEAs).
• Bacillus subtilis hypothetical protein yhcK.
• Caulobacter crescentus pleD protein, a response regulator that controls cell differentiation in the swarmer-to-stalked cell transition.
• Rhizobium celR2, a putative response regulator protein.
• Salmonella protein adrA.

The profile we developed covers the entire GGDEF domain.