This domain is found in human cytoplasmic dynein-2 proteins. Cytoplasmic dynein-2 (dynein-2) performs intraflagellar transport and is associated with human skeletal ciliopathies. Dyneins share a conserved motor domain that couples cycles of ATP hydrolysis with conformational changes to produce movement. Structural analysis reveal that the motor's ring consists of six AAA+ domains (ATPases associated with various cellular activities (AAA1-AAA6). This is the fifth AAA+ domain subdomain AAA5S. Structural analysis reveal that it is the coiled-coil buttress interface. The relative movement of AAA5S together with the stalk (AAA4S), is coupled to rearrangements in the AAA+ ring. Closure of the AAA1 site and the rigid body movement of AAA2-AAA4 force the AAA4/AAA5 interface to close and the AAA6L subdomain to rotate towards the ring centre. The AAA5S subdomain rotates as a unit together with AAA6L, and this movement pulls the buttress relative to the stalk [1].

1: Structure of human cytoplasmic dynein-2 primed for its power stroke. Schmidt H, Zalyte R, Urnavicius L, Carter AP; Nature. 2015;518:435-438. PMID:25470043