Figure 2. pilB^WA suppresses some but not all T4P⁻ pil deletions in EPS production.

EPS levels were analyzed on plates with the fluorescent dye Calcofluor white (See Materials and Methods). The presence of fluorescence indicates EPS⁺ and its absence EPS⁻. Each strip shows two strains, the upper is a strain with the indicated mutation(s) in a pilB⁺ background and the lower in the pilB^WA background. Strains used are YZ690 (ΔpilA), YZ1573 (ΔpilA pilB^WA), DK10417 (ΔpilC), YZ1182 (ΔpilC pilB^WA), YZ1860 (ΔpilM), YZ1185 (ΔpilM pilB^WA), DK11135 (ΔpilG), YZ1183 (ΔpilG pilB^WA), DK11133 (ΔpilH), YZ1181 (ΔpilH pilB^WA), DK11132 (ΔpilI), YZ1184 (ΔpilI pilB^WA), YZ1191 (ΔpilA ΔpilQ) and YZ1190 (ΔpilA ΔpilQ pilB^WA). pilB^WA failed to suppress ΔpilN, ΔpilO, ΔpilP and ΔpilQ as it did ΔpilC and ΔpilM (data not shown).