Fig. 3.

Structure of the EcLon(S679A) open-ring hexamer. (A) Structure of the fragment (235–784) of EcLon(S679A). The AAA⁺ module, consisting of the nucleotide-binding and α-helical domains, the proteolytic domain, the connecting inter-domain linker, as well as the 3-helix bundle preceding the AAA⁺ module are marked. Localization of consensus fragments (Walker motifs A and B, pore-loops 1 and 2, as well as residues Arg finger, Sensor-1 and Sensor-2) is given according to Ref. (Rotanova et al., 2019). (B) Top view cartoon representation with the individual protomers color-coded. (C–D) ¾-tilt and top view CPK representations of the spiral hexamer.