Glycerophosphodiester phosphodiesterase domain of Streptomyces coelicolor cytoplasmic phosphodiesterases UgpQ2 and similar proteins
This subfamily corresponds to the glycerophosphodiester phosphodiesterase domain (GDPD) present in a group of uncharacterized cytoplasmic phosphodiesterases which predominantly exist in bacteria. The prototype of this family is a putative cytoplasmic phosphodiesterase encoded by gene ulpQ2 (SCO1419) in the Streptomyces coelicolor genome. It is distantly related to the Escherichia coli cytoplasmic phosphodiesterases UgpQ that catalyzes the hydrolysis of glycerophosphodiesters at the inner side of the cytoplasmic membrane to produce sn-glycerol-3-phosphate (G3P) and the corresponding alcohols.
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.