Fig. 2: Genes implicated in tailocin sensitivity.

A The RB-TnSeq approach for measuring normalized gene fitness. B Structure of the O-specific antigen LPS of P. aeruginosa PAO1 and enzymes involved in its assembly, based on King et al. [34]. Chemical moieties are abbreviated with the following definitions: Cm O-carbamoyl, D-Ala D-alanine, D-FucNAc 2-acetamido-2-deoxy-D-fucose, D-GalN D-galactosamine, D-Glc D-glucose, D-ManNAc3NAcA 2,3-diacetamido-2,3-dideoxy-D-mannuronate, D-ManNAc3NAmA 2-acetamido-3-acetamidino-2,3-dideoxy-D-mannuronate, GlcNAc N-acetyl-D-glucosamine, Kdo ketodeoxyoctonoate, L-D-Hep L-glycerol-D-manno-heptose, L-Rha L-rhamnose, P phosphorylation (with either one or multiple phosphates or phosphoethanolamines). Select gene function abbreviations are also included: OAL O-antigen ligase, OAP O-antigen polymerase. C Heatmaps depicting fitness scores for all genes in the LPS core oligosaccharide and O-specific antigen clusters, and those in other loci that confer tailocin resistance when mutated. Tailocins were supplied at two different concentrations: maximum concentration (“Max”) and a tenfold dilution from maximum (“Dil”). Tailocin-free buffer was supplied for control experiments (“Ctrl”). All fitness assays were performed in duplicate, and the average fitness is displayed. A gene lacking data means we did not obtain a transposon insertion in it [22]. Genes were annotated in two levels of detail depending on their homology to well-characterized genes. First, all genes were labeled with a function abbreviation. ABC ABC transporter subunit, ACT acetyltransferase, ADT amidotransferase, ANT aminotransferase, AT acyltransferase, C carbamoyltransferase, DA deacetylase, E epimerase, GT glycosyltransferase, I isomerase, IGPS imidazole glycerol phosphate synthase subunit, K kinase, M Mig-14-like, OAL O-antigen ligase, OAP O-antigen polymerase, OAT O-antigen translocase, OCR O-antigen chain length regulator, OR oxidoreductase, UT uridylyltransferase, ? unknown. Then, if a gene’s translation shared ≥60% identity with ≥90% coverage to a characterized gene in P. aeruginosa PAO1, P. aeruginosa PA103, or P. fluorescens SBW25, it was assigned the same gene name. See Supplementary Tables S6–S14 for read count, t-like statistic, and additional fitness data for these genes in Pse05, Pse03, and Pse13. Phenotypes of underlined genes have been validated by spotting tailocin samples on individual mutants (Supplementary Fig. S4 and Supplementary Table S15).