Cytoplasmic dynein carries cargo toward microtubule minus ends. Each motor is a ring of six AAA+ domains with a lever-like linker. A long stalk ends in a microtubule-binding foot. ATP binding closes the ring, primes the linker and releases the foot. Rebinding straightens the linker in the power stroke. Alone, human dynein-1 is mostly inactive. Dynactin and a cargo adaptor switch it on.
8 nm
Yeast dynein. Step size varies from 4 to 24 nm; side and backward steps also occur (Gennerich et al. 2007).
6
AAA+ domains in the ring
32Human DYNC1H1 ranges: AAA1 1868-2099, AAA2 2180-2452, AAA3 2556-2805, AAA4 2899-3168, AAA5 3553-3782, AAA6 4005-4221.
7 pN
Stall force, yeast dynein
13Above stall the motor walks backward toward the plus end. A later study measured 3.6 pN for full-length yeast dynein (Belyy et al. 2016), so reported values differ about twofold.
4.3 pN
Stall force, human dynein-dynactin-BICD2
20Human dynein alone stalled at 2.0 pN in the same study. The complex resists a single kinesin.
about 17 nm
Movement of the linker N-terminus between AAA2 and the stalk base, from negative-stain EM. Separate views and 3D maps gave 13 to 21 nm.
7.4 nm
Linker swing, human dynein-1 (measured)
1Residue 1460 between 9BM0 (primed) and 9BM6 (post-stroke), with the AAA ring superposed. Measured in this work.
about 15 nm
Antiparallel coiled coil between the AAA ring and the microtubule-binding domain. The paper states this length but does not measure it. EM class averages show 10.3-10.5 nm of visible coiled coil (Roberts et al. 2009).
2.2 µM
MTBD affinity, strong registry
22Mouse MTBD on a seryl-tRNA synthetase base; other stalk registries bind at least 10-fold more weakly.