  Relevance of mode coupling to energy/information transfer during protein
function, particularly in the context of allosteric interactions is widely
accepted. However, existing evidence in favor of this hypothesis comes
essentially from model systems. We here report a novel formal analysis of the
near-native dynamics of myosin II, which allows us to explore the impact of the
interaction between possibly non-Gaussian vibrational modes on fluctutational
dynamics. We show that, an information-theoretic measure based on mode coupling
{\it alone} yields a ranking of residues with a statistically significant bias
favoring the functionally critical locations identified by experiments on
myosin II.
