The AAA + ATPase TorsinA polymerizes into hollow helical tubes with 8.5 subunits per turn.
Nature Communications
Demircioglu, F Esra FE; Zheng, Weili W; McQuown, Alexander J AJ; Maier, Nolan K NK; Watson, Nicki N; Cheeseman, Iain M IM; Denic, Vladimir V; Egelman, Edward H EH; Schwartz, Thomas U TU