Glycerophosphodiester phosphodiesterase domain repeat 1 of glycerophosphodiester phosphodiesterase-like protein SHV3 and SHV3-like proteins
This subfamily corresponds to the glycerophosphodiester phosphodiesterase domain (GDPD) repeat 1 present in glycerophosphodiester phosphodiesterase (GP-GDE)-like protein SHV3 and SHV3-like proteins (SVLs), which may play an important role in cell wall organization. The prototype of this family is a glycosylphosphatidylinositol (GPI) anchored protein SHV3 encoded by shaven3 (shv3) gene from Arabidopsis thaliana. Members in this family show sequence homology to bacterial GP-GDEs (EC 220.127.116.11) that catalyze the hydrolysis of various glycerophosphodiesters, and produce sn-glycerol-3-phosphate (G3P) and the corresponding alcohols. Both, SHV3 and SVLs, have two tandemly repeated GDPD domains whose biochemical functions remain unclear. The residues essential for interactions with the substrates and calcium ions in bacterial GP-GDEs are not conserved in SHV3 and SVLs, which suggests that the function of GDPD domains in these proteins might be distinct from those in typical bacterial GP-GDEs. In addition, the two tandem repeats show low sequence similarity to each other, suggesting they have different biochemical function. Most of the members of this family are Arabidopsis-specific gene products. To date, SHV3 orthologues are only found in Physcomitrella patens. This family includes domain I, the first GDPD domain of SHV3 and SVLs.