Common dynamics of globin family proteins.

The recently discovered new members of the globin family, neurogobin and cytoglobin, are the object of sustained structural and functional studies aimed at understanding their physiological role and elucidating the impact of their bis-his heme hexacoordination. However, no studies have yet considered the dynamics of this protein family, an essential link between structure and function. In this communication, we present normal mode analysis results for neuroglobin, cytoglobin, hemoglobin and myoglobin to provide exploratory insights into globin characteristic motions. Our results show a clear correlation in the protein dynamics of this family. All four globins exhibit a high degree of correlated displacements involving residues in the C, E and F helices and link regions. They suggest that these motions play an important role in the reversible oxygen binding function of these proteins. Further, our results may help rationalize some functional features of the 6c-globins in that they alone exhibit correlated displacements of the G-helix region.