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. Chai et al. use cryo-electron microscopy to systematically interrogate the conformational landscape of motor protein dynein. The reported structures reveal intermediate states in the mechanochemical cycle of dynein, the role of adenosine triphosphate and the communication mechanism with microtubules.