Glycerophosphodiester phosphodiesterase domain of mammalian glycerophosphodiester phosphodiesterase GDE4 and similar proteins
This subfamily corresponds to the glycerophosphodiester phosphodiesterase domain (GDPD) present in mammalian GDE4 (also known as glycerophosphodiester phosphodiesterase domain-containing protein 1 (GDPD1)) and similar proteins. Mammalian GDE4 is a transmembrane protein whose cellular function has not yet been elucidated. It is expressed widely, including in placenta, liver, kidney, pancreas, spleen, thymus, ovary, small intestine and peripheral blood leukocytes. It is also expressed in the growth cones in neuroblastoma Neuro2a cells, which suggests GDE4 may play some distinct role from other members of the GDE family.
Comment:The catalytic mechanism of glycerophosphodiester phosphodiesterases is based on the metal ion-dependent general acid-base reaction.
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.