The structure of IdmH. (a, c) Ribbon diagrams showing the IdmH dimer architecture. Individual monomers are coloured green and blue, respectively. The overall shape of the monomer can be described as a distorted α/β-barrel with the dimerization interface located between the β-sheets. Each monomer comprises four α-helices (α1–α4) and five β-strands (β1–β5). (b, d) Surface representation of the IdmH dimer. The surface is coloured using APBS (Jurrus et al., 2018) according to the approximate electrostatic potential from −5 kT e−1 (red) to 5 kT e−1 (blue).