[Unique structural organization of ATP-dependent LonA proteases].

Homooligomeric LonA proteases are the key components of the protein quality control system in bacteria and eukaryotes. Domain organization of the common pool of LonA proteases is determined by comparative analysis of primary and secondary structures of a number of bacterial and eukaryotic enzymes. The similarity of individual enzyme domains was estimated, domain-domain linker areas were revealed, regions that are capable to include intercalated peptide fragments were identified. LonA proteases were shown to be unique AAA+ proteins, because in addition to the classic AAA+ module they contain a part of another AAA+ module, namely the alpha-helical domain including a coiled-coil region, which is similar to the alpha-helical domain of the AAA(+)-1 module of the chaperone-disagregases ClpB/Hsp104.