FIGURE 9.

Proposed model for the interconversion between the extracellular and intracellular facing NorM-NG. Rotational movement alone between the N (cyan) and C (yellow) domains is unlikely to bring all the five cysteine pairs studied in this work (blue dots) into sufficient proximity for disulfide formation. Helix bending (highlighted by a red arrow) likely occurs as the transporter adopts the intracellular facing conformation, which enables the disulfide bond formation (red dots). Although helix bending may occur in the N and/or C domain, for simplicity the bending of helices is only shown in the C domain.