A domain similar to OmpA (IPR006665) is many outer membrane proteins of gram-negative bacteria, having a domain with a β/α/β/α-β(2) structure at their C terminus. This includes porin-like integral membrane proteins (e.g. ompA), small lipid-anchored proteins (e.g. pallin), and the N-terminal half of the MotB proton channel (IPR000498). In E. coli, MotB and MotA have two functions: the first is to attach the MotA(4)-MotB(2) complex to the cell wall via MotB to form the stator of the flagellar motor. The other is to connect the movement of the rotor to the flow of ions across the cell membrane. Dynein N-terminal heavy chain 1N(F08385). Eukaryotic dyneins are often called "motor proteins". They can turn the energy released when ATP breaks down into forces and movements along polymers in the cytoskeleton, such as microtubules. The Dynein_C, the C-terminal domain of the Dynein heavy chain(IPR041228), is the dynein heavy chain's C-terminal domain.