Fig. 2.

Relationship between exon organization and polypeptide structure of the L/B/K ALP gene. L/B/K ALP gene exons 1–12 are shown as large rectangles. Untranslated regions are indicated by green colour. The signal peptide at the amino terminus and the hydrophobic stretch of amino acids at the carboxyl terminus in exons 2 and 12, respectively, are shown in yellow. Regions which comprise the active pocket that are conserved in intestinal ALP, placental ALP, and E. coli ALP are shown as follows: small rectangles above the exons indicate conserved units of amino acid sequence which exist as discrete units of secondary structure in E. coli ALP (black for & sheets, white for a-helices); the open circles indicate metal ligands, and the closed circles indicate residues that directly interact with incoming substrate