Fig. 1. Cryo-EM analysis of AdhE spirosomes.

a Negative staining electron microscope images of AdhE spirosomes in the absence (left) and the presence (right) of the cofactors (50 μM Zn²⁺, 500 μM NAD⁺, and 10 mM ethanol). AdhE stably exists in an extended conformation in the presence of the cofactors. The scale bars show 50 nm. b A representative micrograph (left) and 2D class averages (right). The scale bars show 50 nm. c The 3.43 Å resolution cryo-EM maps of AdhE spirosomes in an extended conformation.