Dynein heavy chain, hydrolytic ATP-binding dynein motor region
IPR035699
Definition
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 PMID:11250194. 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 PMID:25470043. Dyneins are motor proteins of eukaryotic cells that convert energy from ATP hydrolysis into force and movement along microtubules. They generally contain one to three heavy chains (each >500kDa), which belong to the AAA+ superfamily of mechanochemical enzymes, along with several accessory subunits ranging from light to intermediate chains. Each heavy chain consists of a flexible N-terminal tail known as the cargo-binding domain and a motor domain. The motor domain comprises an ATP-hydrolysing AAA+ ring (formed by six AAA domains), a linker, a stem, a C-sequence, and a stalk with a long coiled-coil structure. The stalk contains an ATP-sensitive microtubule-binding site at its tip, while the linker functions as a mechanical element for generating dynein's power stroke. Studies using a 380kDa recombinant fragment of the Dictyostelium dynein heavy chain demonstrated that the C-terminal two-thirds maintains microtubule-activated ATPase activity and drives robust microtubule sliding, confirming this region as the functional motor domain PMID:22398446. Two categories of dyneins exist: axonemal dyneins, which produce bending motions that propagate along cilia and flagella, and cytoplasmic dyneins, which drive fundamental cellular processes including nuclear migration, mitotic spindle organisation, chromosome separation, and the positioning and function of intracellular organelles [[cite:PMID:16061793], [cite:PMID:8666668], [cite:PMID:16229832]].
16 human proteins with this domain
Each is a reviewed human protein in the Seroatlas serome and a potential autoantibody target; this domain groups them into one antibody-relevant category. Every entry links to its own record.
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