Modeling conformational change in macromolecules as an elastic deformation

Macromolecules are elastic bodies. Atomic structures are available for nucleic acids and proteins in two or more different conformations. It is a common practice to compare two structures by finding the best rigid body superposition of the molecules. This ignores possible deformations. There is useful information in the deviations from the rigid body superposition. If the deviations are considered to be elastic deformations of a common structure than it is possible to extract this information. Results are shown for comparisons of deoxyhemoglobin versus carbonmonoxyhemoglobin and for two different conformations of catabolite gene activator protein.