This entry includes a wide variety of AAA domains, including some that have lost essential nucleotide binding residues in the P-loop. This domain is found in Lon proteases from archaea and bacteria [1].

1: Structures of an ATP-independent Lon-like protease and its complexes with covalent inhibitors. Liao JH, Ihara K, Kuo CI, Huang KF, Wakatsuki S, Wu SH, Chang CI; Acta Crystallogr D Biol Crystallogr. 2013;69:1395-1402. PMID:23897463