TRIOSE PHOSPHATE ISOMERASE

This protein contains both alpha helices and beta sheets. There are two main classes of these proteins. In one class, represented by this enzyme, the parallel beta strands form a closed "beta" barallel, made up of 8 twisted beta strands. Connecting the beta strands are alpha helices, so the protein contains an baba..repeat. The alpha helices are on the outside of the barallel. This specfic motiff that is found in many proteins is often called the TIM barallel after this particular protein. The active site of these proteins at the top of the barallel where loops that connect the C-terminal ends of the beta strands connect the adjacent alpha helix.