Extended Data Fig. 8: Nucleotide-bound conformations of Cgt.
From: Mechanism of cyclic β-glucan export by ABC transporter Cgt of Brucella
a-c, Top view from the periplasmic side of Cgt highlighting the hydrophobic ‘isoleucine gate’ formed by residues I46 and I276. The gate is closed in the inward-facing state (CgtAPO, a) as wells as in the closed-occluded conformation (CgtVAN, b). In the inward-facing CgtDET structure (c), the gate is open, allowing access from the central cavity to the periplasmic space. d, Periplasmic side of Cgt TM helices, indicating the proposed mechanism for opening of the central cavity to the outside. Chain A shown in purple and pink; chain B shown in blue and cyan. A CβG molecule (blue-red sticks) was docked into the central cavity. Rearrangements of TMs and periplasmic loops between the CgtVAN (left) and CgtDET (right) models are indicated with arrows. The resulting opening allows the release of the substrate into the periplasmic space (grey arrow).
