TL;DR: A conformational analysis of the five snapshots of PhNTPase structures using the multiple superposition method reveals that IMP, ITP and Mn(2+) bind to the active site without inducing large local conformational changes, indicating that a combination of interdomain and interprotomer rigid-body shifts mainly describes the conformational change of PhnTPase.
TL;DR: Findings suggest that in platelet actomyosin, actin enhances the cooperativity of nucleotide binding sites of myosin by reducing the K m for ATP or UTP, which may not be necessarily identical to those induced by ATP orUTP.