InterPro domain: IPR035699

Dyneins are multiprotein complexes that move cargo along microtubules in the minus end direction. The largest component of the dynein complex is the heavy chain. Its C terminus forms the motor unit [ 1 ].

The 380kDa motor unit of dynein belongs to the AAA class of chaperone-like ATPases. The core of the 380kDa motor unit contains a concatenated chain of six AAA modules, of which four correspond to the ATP binding sites with P-loop signatures described previously, and two are modules in which the P loop has been lost in evolution. This domain is the D1 unit of the motor and contains the hydrolytic ATP binding site [ 2 ].

This is the AAA1 large (AAA1L) subdomain with the accompanying small subdomain (AAA1S). AAA1L, AAA1S and AAA2L enclose ADP.vanadate (ADP.Vi, ATP-hydrolysis transition state analogue). The AAA1L sensor-I loop, which varies in position depending on dynein's nucleotide state, swings in to contact AAA2L forming the important AAA1 nucleotide-binding site [ 3 ].

1. Review: Structure and mechanism of the dynein motor ATPase. Biopolymers 105, 557-67
2. Model for the motor component of dynein heavy chain based on homology to the AAA family of oligomeric ATPases. Structure 9, 93-103
3. Structure of human cytoplasmic dynein-2 primed for its power stroke. Nature 518, 435-8