Structure and Dynamics of F-actin: Conformational Change of Actin Molecule Induced by Polymerization

Abstract

Actin molecule has two major domains which enclose a nucleotide-binding cleft. On the basis of domain arrangement, conformation of actin molecule has been classified into two categories “closed” and “open”. We find a novel flat conformation of actin molecule in F-actin structure using the X-ray fiber diffraction method. The flat conformation is generated by relative rotation of two major domains. The flat conformation is deduced to be important for both the filament formation and the actin ATPase.