Extended Data Fig. 9: Increased levels of pentapeptide-rich PG diminishes midcell bias of OMP biogenesis.

(A) Epifluorescence images of FepA, labelled with ColB-GFP in the indicated strains with or without induction of FepA expression. (B) Epifluorescence and 3D-SIM images of newly synthesised FepA in the indicated strains after 7 min induction (0.4% arabinose). Red arrows indicate cells exhibiting atypical biogenesis patterns compared to the CS109 parent strain. (C) Distribution of FepA localisation along normalised cell lengths in the strains from panel B (± SD, 3 biological replicates). (D) Normalised fluorescence intensity across the long-axis of multiple cells. Shown are demographs of FepA labelling 7 min after induction of the indicated strains. These charts and the images in panel B demonstrate the incoherent and reduced midcell bias for OMP biogenesis in the pentapeptide-rich strain. (E) Co-labelling of BamA, PG and OMP biogenesis in a penta-rich strain (CS703). HADA was added 3 min after FepA induction and the total induction time was 10 min. Arrows indicate septa where no increased OMP biogenesis was observed. (F) Epifluorescence (top) and 3D-SIM (bottom) images of the indicated strains labelled with αBamA^AF488 Fabs. The images highlight that BamA organization is similar despite the changes in PG composition. (G) Comparison of BamA distribution in the strains from panel F. Shown are integrated localization maps (top) and charts showing the distribution of islands along the long axis of the cells (bottom). The charts show that BamA is uniformly distributed in all strains. Scale bars, 1 μm.