Journal: Nature Communications
Article Title: Molecular mechanism of action of small molecule SMT-738 on bacterial lipoprotein transporter LolCDE
doi: 10.1038/s41467-026-69411-2
Figure Lengend Snippet: a The same amounts of purified LolCDE and LolCDE-SMT-738 complexes were loaded onto a blue native-PAGE gel. After electrophoresis, the blue native-PAGE gel was stained with Coomassie brilliant blue. The protein samples in the blue native-PAGE gel were also detected with using anti-His monoclonal antibody. The general non-denaturing protein marker is not shown in the PVDF membrane. All experiments were repeated three times. b Structural superimposition of the apo-LolCDE structure (PDB code: 7MDY, gray) to the LolCDE-SMT-738 structure shows the minor conformational shifts of residues interacting with SMT-738 identified in LolC or LolE: LolC residues (grape purple sticks) E195 (0.9 Å), E255 (1.1 Å), L256 (1.1 Å), A259 (0.7 Å), and LolE residues (electric blue sticks) I59 (1.4 Å), M261 (1.5 Å), D264 (1.5 Å) and F367 (4.0 Å). c Structural superimposition also shows a shift of the coupling helix of LolE (electric blue cartoon) in the LolCDE-SMT-738 structure toward LolC by approximately 5.5 Å in the red dashed square, and the LolD bound to LolE shifted approximately 5.2 Å toward LolC. d The clash between LolD bound to LolE in the LolCDE-SMT-738 structure and LolD bound to LolE in the apo-LolCDE structure (PDB code: 7MDY). e Structural superimposition shows a shift of the coupling helix of LolC in the LolCDE-SMT-738 structure (grape purple cartoon) toward LolE by approximately 11.4 Å in the red dashed square. f ATPase activity of LolCDE, ATPase-deficient variant LolCD (E171Q) E (negative control) and SMT-738-bound LolCDE complexes. Experiments were performed in triplicate. Data are presented as mean ± SD ( n = 3 replicates). A two-tailed Student’s t test was used for group comparisons. **** p < 0.0001, exact p values, LolCDE vs LolCD (E171Q) E, p = 3.3426E-08, LolCDE vs SMT-738 bound LolCDE, p = 7.06424E-08. Source data are provided as a file.
Article Snippet: Immunodetection was performed using mouse monoclonal anti-His antibody (Proteintech, Catalog No: 66005-1-Ig; 1:5000 dilution), followed by incubation with HRP-conjugated anti-mouse IgG (Proteintech, Catalog No: SA00001-1; 1:10000 dilution).
Techniques: Purification, Blue Native PAGE, Electrophoresis, Staining, Marker, Membrane, Activity Assay, Variant Assay, Negative Control, Two Tailed Test