Fig. (1) Crystal structure of alkaline phosphatase from E. coli (A) and human placenta (B) highlighting the structural similarity between bacterial and mammalian forms of the enzyme. Monomer subunits are coloured differently to highlight the dimeric nature of the enzymes. Coordinates of the structures were downloaded from http://www.rcsb.org/pdb and the images were produced using PyMOL [22]. The pdb accession numbers are ALK1 (E. coli alkaline phosphatase) and 1EW2 (human placental alkaline phosphatase).