Structural and ensemble-based mechanistic insights into cytoplasmic dynein-1.

Cytoplasmic dynein-1 is a multi-subunit motor that transports diverse cargoes toward microtubule minus-ends, playing crucial roles in intracellular organisation and cell division. Over the past decade, X-ray crystallography and cryo-EM approaches have captured numerous high-resolution structures of dynein's components and complexes ranging from motor domain structures and microtubule binding domain (MTBD)-tubulin complexes, to the autoinhibited and open dynein dimers, activated dynein-dynactin-adaptor assemblies, and LIS1-bound intermediates. These findings have highlighted dynein's architecture and partial conformational cycle, including key intermediates in its activation and assembly with dynactin and cargo adaptors. However, a unified molecular model that links ATP hydrolysis at multiple AAA+ sites to the coordinated motions of dynein's components and their regulation by dynactin, cargo adaptors, and LIS1 remains elusive. Existing mechanistic models rely on discrete structural states and simplified kinetic schemes, which fail to capture conformational heterogeneity and regulator-specific effects. In this mini review, we summarise the current structural and mechanistic knowledge of cytoplasmic dynein-1, highlighting the motor's stepping mechanism and cofactor functions. We then discuss computational approaches including molecular dynamics simulations, enhanced sampling techniques, and integrative modelling that can merge these specific states into quantitative conformational landscapes. This ensemble view will be helpful for understanding dynein's mechanism from a dynamical perspective.