Fig. 2: Single-particle cryo-EM structure of BtBAM.
From: Structure of a distinct β-barrel assembly machinery complex in the Bacteroidota
a, Refined cryo-EM density maps of the final two 3D classes. b, Model built into the cryo-EM maps. The SLP models were refined against the class 1 density in which the extracellular region was better resolved. The BamADG models were refined against class 2, in which BamA and BamD density was better resolved. The refined SLP models were rigid body docked into the class 2 map, resulting in the final model. c, Close-up view of the BamA β-barrel seam. Residues 458–472, comprising most of the β1 strand, extracellular loop 1 and part of the β2 strand, are not resolved in the cryo-EM maps. d, The SLPs form an extracellular dome, which partially encloses a ~90,000-Å3 volume above the OM. The white arrowhead in the right panel indicates the lateral opening of the BamA β-barrel, with BamD omitted for clarity.
