  Single molecule and NMR measurements of protein dynamics increasingly uncover
the complexity of binding scenarios. Here we describe an extended
conformational selection model which embraces a repertoire of selection and
adjustment processes. Induced fit can be viewed as a subset of this repertoire,
whose contribution is affected by the bond-types stabilizing the interaction
and the differences between the interacting partners. We argue that protein
segments whose dynamics are distinct from the rest of the protein ('discrete
breathers') can govern conformational transitions and allosteric propagation
that accompany binding processes, and as such may be more sensitive to
mutational events. Additionally, we highlight the dynamic complexity of binding
scenarios as they relate to events such as aggregation and signalling, and the
crowded cellular environment.
