ATP-dependent proteases in plant mitochondria: What do we know about them today?

Lon‐, Clp‐ and FtsH‐like proteases, members of three families of ATP‐dependent proteases derived from bacterial ancestors, have been identified in plant mitochondria. Classifications of mitochondrial‐specific paralogues of plant ATP‐dependent proteases, based on targeting prediction programs and different experimental methods, are compared. Accumulating evidence points to similarities in the structure and the mechanisms of action used by various ATP‐dependent proteases. Therefore, before focusing on plant mitochondrial ATP‐dependent proteases, the paper discusses general features of ATP‐dependent proteases. To date, information about structure and function of plant mitochondrial Lon‐like, Clp‐like and FtsH‐like proteases is rather scarce, but indicates that these enzymes, like their bacterial and eukaryotic homologues, combine proteolytic and chaperone‐like activities to form mitochondrial protein quantity and quality control system in plants.