Abstract
Rotary ATPases, including F(1)F(O)-, V(1)V(O)-, and A(1)A(O)-ATPases, are molecular motors that exhibit rotational movements for energy conversion. In the gliding bacterium, Mycoplasma mobile, a dimeric F(1)-like ATPase forms a chain structure within the cell, which is proposed to drive the gliding motility. However, the mechanisms of force generation and transmission remain unclear. We determined the electron cryomicroscopy (cryo-EM) structure of the dimeric F(1)-like ATPase complex. The structure revealed an assembly distinct from those of dimeric F(1)F(O)-ATPases. The F(1)-like ATPase unit associated by two subunits GliD and GliE was named G(1)-ATPase as an R(1) domain of rotary ATPases. G(1)-β subunit, a homolog of the F(1)-ATPase catalytic subunit, exhibited a specific N-terminal region that incorporates the glycolytic enzyme, phosphoglycerate kinase into the complex. Structural features of the ATPase displayed strong similarities to F(1)-ATPase, suggesting a rotation based on the rotary catalytic mechanism. Overall, the cryo-EM structure provides insights into the mechanism through which G(1)-ATPase drives the Mycoplasma gliding motility.