Extended Data Figure 5: The conformational changes between the BamABCDE and BamACDE complexes and heat-modifiability assays of the BamA double cysteine mutants.
From: Structural basis of outer membrane protein insertion by the BAM complex
The two structures are superimposed onto the BamA barrel structures of BamABCDE and BamACDE complexes with a r.m.s.d. of 4.85 Å over the 379 barrel Cα atoms and a maximum r.m.s.d. of 20 Å. The POTRA domains align with an r.m.s.d. of 5.764 Å over 384 Cα atoms with maximum 15 Å. The BamABCDE complex is in the same colour scheme as Fig. 1. The BamACDE complex is in yellow. The barrel strands β1C–β6C rotate around 65° from BamABCDE to BamACDE, while the BAM periplasmic unit rotates around 30° in a anti-clockwise direction from BamABCDE to BamACDE. a, Membrane view of the superimposition of the BamABCDE and BamACDE complexes. The conformations of BamA POTRA domains, BamB, BamC and BamD are considerably different between the two complexes. b, The periplasmic view of the superimposition of BamABCDE and BamACDE. The circular units rotate around 30° between the two BAM complexes. c, The residues involved in closing the barrel at the periplasmic side in the BamACDE structure. d, Heat-modifiability assays of the BamA double cysteine mutants. SDS–PAGE/western blot analysis of the wild-type BamA, BamA Gly393Cys/Gly584Cys, Glu435Cys/Ser665Cys and Glu435Cys/Ser658Cys mutants showed the heat-modifiability, indicating that the three double cysteine BamA mutants were correctly folded into the OM. F, folded; U, unfolded. See Supplementary Fig. 5.
