The mechanochemical cycle of reactive full-length human dynein 1

Abstract

Dynein-driven cargo transport has a pivotal role in diverse cellular activities, central to which is dynein’s mechanochemical cycle. Here, we performed a systematic cryo-electron microscopic investigation of the conformational landscape of full-length human dynein 1 in reaction, in various nucleotide conditions, on and off microtubules. Our approach reveals over 40 high-resolution structures, categorized into eight states, providing a dynamic and comprehensive view of dynein throughout its mechanochemical cycle. The described intermediate states reveal mechanistic insights into dynein function, including a ‘backdoor’ phosphate release model that coordinates linker straightening, how microtubule binding enhances adenosine triphosphatase activity through a two-way communication mechanism and the crosstalk mechanism between AAA1 and the regulatory AAA3 site. Our findings also lead to a revised model for the force-generating powerstroke and reveal means by which dynein exhibits unidirectional stepping. These results improve our understanding of dynein and provide a more complete model of its mechanochemical cycle.