This domain represents the helical domain found in the Lon-like LonC protease from Meiothermus taiwanensis [1], a Lon-like protease with no ATPase activity.

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