Figure 1. The BcAU1054 T6SS mediates interbacterial competition.

(A) Core cluster (top two lines) and accessory genes encoding the BcAU1054 T6SS and predicted effector-immunity (E-I) pairs (see Table S2). The legend indicates function of protein products. White ORFs encode DUF4123 T6SS adapter proteins, or proteins not known to be associated with the T6SS. (B and C) Competition experiments between inhibitor BcAU1054 and target E. coli (B) and B. dolosa (C). WT, Δhcp, and Δhcp attTn7::hcp BcAU1054 inhibitor strains used in each. Circles represent individual cocultures from two biological replicates, each with four technical replicates. Solid horizontal lines represent mean log₁₀ C.I. values. Dotted horizontal lines (log₁₀ C.I. = 0) indicate no competitive advantage for either strain. *P<0.05, **P<0.0005, Mann-Whitney test.