Fig. 3. Structure-based sequence alignment of human and P.mevalonii HMGR (PDB code 1qax; Tabernero et al., 1999). Colors of the secondary structure elements are as in Figure 1C; solid arrows indicate β–strands, outlined rectangles indicate α–helices and an asterisk indicates a 3₁₀-helix. Regions of high structural similarity are in yellow, residues involved directly in substrate binding are in purple and regions involved in dimerization or tetramerization are marked by the words ‘dimer’ and ‘tetramer’. The phosphorylation site (S872) of human HMGR is marked in green.