cl11083

C-terminal, D2-small domain, of ClpB protein; This is the C-terminal domain of ClpB protein, referred to as the D2-small domain, and is a mixed alpha-beta structure. Compared with the D1-small domain (included in AAA, pfam00004) it lacks the long coiled-coil insertion, and instead of helix C4 contains a beta-strand (e3) that is part of a three stranded beta-pleated sheet. In Thermophilus the whole protein forms a hexamer with the D1-small and D2-small domains located on the outside of the hexamer, with the long coiled-coil being exposed on the surface. The D2-small domain is essential for oligomerization, forming a tight interface with the D2-large domain of a neighbouring subunit and thereby providing enough binding energy to stabilize the functional assembly. The domain is associated with two Clp_N, pfam02861, at the N-terminus as well as AAA, pfam00004 and AAA_2, pfam07724.