Extended Data Fig. 3: ECOR14 signature-tagged mutagenesis uncovers that curli is required for B. bacteriovorus defense.
From: Functional amyloid proteins confer defence against predatory bacteria
(a) Overview of ECOR14 transposon mutagenesis and screen for B. bacteriovorus defense. ECOR14 was transposon-mutagenized and 6,734 individual mutants were gridded into multi-well plates. Each mutant was individually challenged B. bacteriovorus HD100; in these conditions, wells with wild-type ECOR14 became turbid from E. coli growth while wells with newly-susceptible mutants were cleared by B. bacteriovorus. Mutants that failed to defend were rescreened by plaque assay with a B. bacteriovorus HD100 dilution series (indicated from 100–10−5), as in Extended Data Fig. 1b. The transposon insertion site was mapped for confirmed susceptible mutant strains. (b) Efficiency of plating, calculated as PFU/mL, of B. bacteriovorus HD100 when infecting the indicated strains of E. coli. Details of each Tnmut can be found in Supplementary Table 2. Data graphed as in Fig. 1b. (c) Organization of the two curli operons underlying curli production along with a graphical representation of how curli fibres are formed on the outer membrane. Briefly, CsgBAC and CsgEFG are secreted via Sec to the periplasmic space. Here CsgEFG form the secretion apparatus required for CsgA and CsgB to cross the outer membrane32. CsgC aids CsgA folding at the proper location35. CsgB is the membrane anchor that seeds CsgA oligomerization and curli fibre formation52. See Supplementary Table 3 for protein accession numbers. (d) Efficiency of plating, calculated as PFU/mL, of B. bacteriovorus 109J when infecting the indicated strain of ECOR14. Data graphed as in Fig. 1b.
