Exploring the Origin of Directionality of Ncd Motor using Structure-Based Model

Abstract

Ncd motor proteins are the member of kinesin superfamily which serve important purpose in terms of cargo transport upon microtubule track. While the Ncd proteins are structurally very similar to other proteins of kinesin family, they move towards the negative end of microtubule as opposed to others. Here, we explore the origin of such unique directionalily of Ncd motor proteins using structure-based model and identify the important structural elements responsible for the motion. We find that the flexibity of the junction region between coiled-coil stalk and motor head acts as ATP dependent switch to create specific directionality. We also identify the nature of domain motion in free Ncd using covariance analysis which describes the symmetry breaking character of conformtional fluctuation. The novelty of our present study is that simple structure-based model can describe the essential feature of complex functionality of Ncd motors.