Conformational Ensembles from Experimental Data and Computer Simulations

Conformational Ensembles from Experimental Data and Computer Simulations

Poster Abstracts

22-POS Board 22 Temporal Correlations Among Functionally Important Distant Residues of Ubiquitin Sutapa Dutta , Mahua Ghosh, Jaydeb Chakrabarti. S. N. Bose National Centre for Basic Sciences, Salt Lake City, Kolkata, West Bengal, India. Long distant coupling between distant binding sites in bio-macromolecules is a fundamental challenge in uncovering their functions. We study the microscopic basis of such communication through time dependent dihedral cross-correlation functions among spatially separated yet functionally important residues of a small protein, named ubiquitin which participates in degradation of mis-folded protein in eukaryotes. We perform 1.05 micro-second long all atom Molecular Dynamics simulation. We observe that the dihedral angles of the residues possess non-trivial temporal cross-correlations with asymmetry with respect to exchange of the dihedrals, having peaks at low frequencies with time scales in nano-seconds and an algebraic tail with a universal exponent for large frequencies. We show the existence of path for temporally correlated degrees of freedom among the functional residues. We explain the qualitative features of the cross-correlations through a general mathematical model. The generality of our analysis suggests that temporal cross-correlation functions may provide convenient theoretical framework to understand bio-molecular functions on microscopic basis.

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