(a). Details of the Trp loop and lid regions in the open wild-type structure (orange and red, respectively, PDB code 6FWT) and in the open mutated structure (gray, PDB code 2FY7). (b). Details of the Trp loop and loop1 regions in the closed wild-type structure (orange and blue, respectively, PDB code 6FWU) and closed mutated structure (gray, PDB code 4EE4). (c, d). Root mean square deviation (RMSD) of atomic positions in pairwise comparisons plotted by residue number between 6FWT and 2FY7 (c), and 6FWU and 4EE4 (d). Differences (RMSD > 2 Å) are highlighted by arrows. Residues that could not be traced in the crystal structures were omitted in the RMSD plot (343–351 in 2FY7, 345–363 in 6FWU).