Glycerophosphodiester phosphodiesterase domain of Agrobacterium tumefaciens and similar proteins
This subfamily corresponds to the glycerophosphodiester phosphodiesterase domain (GDPD) present in Agrobacterium tumefaciens glycerophosphodiester phosphodiesterase (AtGDE, EC 18.104.22.168) and its uncharacterized eukaryotic homolgoues. Members in this family shows high sequence similarity to Escherichia coli GP-GDE, which catalyzes the degradation of glycerophosphodiesters to produce sn-glycerol-3-phosphate (G3P) and the corresponding alcohols. AtGDE exists as a hexamer that is a trimer of dimers, which is unique among current known GDPD family members. However, it remains unclear if the hexamer plays a physiological role in AtGDE enzymatic function.
Comment:Based on structure evidence and site-directed mutagenesis of Thermoanaerobacter tengcongensis glycerophosphodiester phosphodiesterase, the catalytic site consists of two conserved histidine residues which serve as general acid and general base in catalyzing the hydrolysis of the 3'-5' phosphodiester bond.