Fig. 3: The LPS structures recognized by PilV adhesins are part of the core-oligosaccharide in E. coli. | Communications Biology

Fig. 3: The LPS structures recognized by PilV adhesins are part of the core-oligosaccharide in E. coli.

From: Systematic investigation of recipient cell genetic requirements reveals important surface receptors for conjugative transfer of IncI2 plasmids

Fig. 3

a Schematic representation of TP114 shufflon where the 3’-end of pilV can undergo DNA rearrangement catalyzed by the shufflase (rci), a tyrosine recombinase that swaps the DNA segments comprised between two conserved recombination motifs (sfx sites). Only one possible conformation is shown. b DNA rearrangement of the shufflon in the donor bacterium allows the expression of eight different adhesins, presumably at the tip of the type IVb pilus. c General chemical structure of LPS from Gram-negative enterobacteria. LPS consists of the membrane-anchoring lipid A ___domain and a covalently linked polysaccharide or oligosaccharide portion. The depicted scheme represents the LPS architecture of E. coli BW25113 which corresponds to the distinct core structure termed K-12. Even though E. coli BW25113 lack long O antigen because the wbbL gene is interrupted by an IS5 insertion, we generate a mutant in which the rfbABCD, wzxB, glf, and wbbHIJKL genes were removed so that any of the O16 antigen molecules could be produced. The terminal glucosamine (GlcN) molecule is part of the O16 antigen but is still present in the BW25113ΔO antigen mutant since its incorporation only required the functions of wecA (rfe), an undecaprenyl-phosphate α-N-acetylglucosaminyl transferase, and wzx, an O antigen translocase, which are both in other operons elsewhere in the chromosome64. ClearColi only displays the lipid IVA which lacks the two secondary acyl chains and does not contain polysaccharides39. d Heat-map illustrating the transfer rates of wild-type TP114 along with the eight fixed pilV variants against various E. coli recipient cells. Transfer rates of the TP114ΔpilV::FLAG-cat mutant in which the variable region of pilV was replaced by a FLAG tag are also shown. All adhesins can transfer to at least one strain in broth. All conjugations were performed in biological triplicate with E. coli Nissle 1917ΔdapA as the donor strain. Cross marks indicate conjugation frequencies below the detection limit of the experiment (1 × 10−8). Created in Biorender.com.

Back to article page