GHKL, an emergent ATPase/kinase superfamily.

An interesting recent development is the recognition of a novel ATP-binding superfamily that includes diverse protein families such as DNA topoisomerase II, molecular chaperones Hsp90, DNA-mismatch-repair enzymes MutL and histidine kinases. The most singular unifying feature of this superfamily is the unconventional Bergerat ATP-binding fold. The far-reaching significance of this commonality is still in the process of being explored.