Bacterial alkaline phosphatase structure

Metal ions also participate in the functioning of other nucleases, although the structural details of their participation are not nearly as established as those for staphylococcal nuclease. DNAse I also requires Ca for its catalytic activity.SI endonuclease, mung bean nuclease, and Physarum polycephalem nuclease require zinc ion either as cofactors or intrinsically for nuclease activity, and the restriction enzyme EcoRI may also require intrinsically bound zinc ion. In terms of how the zinc ion might function in these enzymes, one can look both to staphylococcal nuclease and to bacterial alkaline phosphatase for some... 

The GPIs started being recognized a unique tool for membrane anchoring after first observations that bacterial phosphatidylinositol phosphoHpase C releases alkaline phosphatase, 5 -nucleotidase, and acetylchoHnesterase from various tissues in soluble form suggesting that these proteins are localized at the periphery of the cell membrane by a phosphatidylinositol-containing Hpid [3, 4]. Further studies on these and other eukaryotic proteins led to the first fuU structural elucidation of a GPI molecule, the Trypanosoma brucei variant surface glycoprotein (VSG) GPI anchor [5, 6]. 

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