Fig. 4: Characterisation of FimTLp binding to DNA in vitro and in vivo.
From: The molecular basis of FimT-mediated DNA uptake during bacterial natural transformation
MST/TRIC binding assay of 12 bp FAM-labelled dsDNA with a, wild-type FimTLp performed at different NaCl concentrations (ionic strength) and b, wild-type FimTLp compared to FimT mutants predicted to disrupt DNA binding based on Fig. 3. n.d., not determined. The MST/TRIC data were fitted according to two binding sites with equal affinity. Error bars represent the mean ± SD (n = 3). c, d, Natural transformation efficiencies of parental Lp02, Lp02 ΔfimT, and the Lp02 ΔfimT strain complemented by ectopic expression of wild-type and FimTLp mutants that disrupt DNA binding (c) or do not contribute to DNA binding according to Fig. 3 (d). The mean transformation efficiencies of three independent biological replicates are plotted with error bars representing the SD. < d.l., below detection limit (d.l.) (average d.l. = 2.0 × 10−8 ± 8.2 × 10−9 (c) and 2.5 × 10−8 ± 9.5 ×10−9 (d)); #, below d.l. in at least one replicate (average d.l. used to calculate the mean transformation efficiency). The assay in panel c was performed in parallel to those displayed in Fig. 1a, and statistical differences were determined on log-transformed data using an unpaired two-sided t-test with Welch’s correction. The Lp02 ΔfimT strain complemented with mutants was compared to the Lp02 ΔfimT strain complemented with wild-type FimT, which was in turn compared to the parental strain. **, p < 0.01 (pR143Q = 0.003; pR146Q = 0.002; pR148Q = 0.004); n.s., not statistically significant, p > 0.05 (pWild-type(c) = 0.89; pWild-type(d) = 0.33; pS107Q = 0.38; pS122Q = 0.08; pG150Q = 0.89). Source data are provided as a Source Data file.
