InterPro domain: IPR042219

Dyneins can be divided into two groups: cytoplasmic dyneins and axonemal dyneins, which are also called ciliary or flagellar dyneins.

Dyneins power the beating of cilia and flagella, transport various intracellular cargos and are necessary for mitosis. All dyneins have a 300kDa motor domain consisting of a ring of six AAA domains. ATP hydrolysis in the AAA ring drives the cyclic relocation of a motile element, the linker domain, to generate the force necessary for movement [ 1 ].

The cytoplasmic dynein is composed of two identical heavy chains (each >500kDa) and a number of smaller chains. The dynein heavy chain, which belongs to the AAA superfamily of mechanochemical enzymes, is responsible for the motor activities of dynein [ 2 ]. The heavy-chain folds into a ring-like head composed of six AAA domains, a stem, and a stalk emerging from the head. The stalk is the microtubule-binding domain with a long coiled-coil structure [ 3 ]. The 380kDa recombinant fragment of the C-terminal two-thirds of the Dictyostelium dynein heavy chain [ 4 ] maintains microtubule (MT)-activated ATPase activity and drives robust MT sliding, showing that this fragment is the motor domain of the Dictyostelium dynein [ 5 ].

This superfamily represents the AAA lid domain found near the C-terminal region of dynein heavy chain.

1. Insights into dynein motor domain function from a 3.3-A crystal structure. Nat. Struct. Mol. Biol. 19, 492-7
2. C-sequence of the Dictyostelium cytoplasmic dynein participates in processivity modulation. FEBS Lett. 585, 1185-90
3. A single-headed recombinant fragment of Dictyostelium cytoplasmic dynein can drive the robust sliding of microtubules. J. Biol. Chem. 279, 22799-802
4. Overexpression of cytoplasmic dynein's globular head causes a collapse of the interphase microtubule network in Dictyostelium. Mol. Biol. Cell 7, 935-48