Correspondence between global and local changes in bound/unbound chains. a) Cα rmsd (x axis) versus percentage of modified structural letters (y axis). Open circles: enzyme-substrate, plain squares: antigen-antibody, crosses: other. One chain of complex 1H1V, with a rmsd equal to 14 Å and 55% of modified structural letters is outside the range of this plot. The regression line shown on the plot is obtained by excluding chains with rmsd greater than 4.5 Å. Dashed line indicate the values obtained for the control set: 28% of modified letter, 0.30 Å rmsd. b) Superimposition of structures with high rmsd and low percentage of modified letters. Chain A of the receptor part of complex 2VIS (hemagglutinin from Influenza virus complexed with immunoglobulin): rmsd = 4.9 Å, 26% of local change. c) Superimposition of structures with low rmsd and many local changes, with corresponding structural letter encoding. Chain A of the receptor part of complex 1I4D (Rac1-GDP complexed with arfaptin from human), rmsd = 0.88 Å, 75% of local change, and chain B of the receptor part of complex 1F51 (transferase complex form bacillus subtilis) rmsd = 1.45 Å, 69% of local change. Orange: unbound conformations, green: bound conformations.