Genomic analysis of GBS T7SS subtypes and characterization of the GBS T7SS operon in subtype I strain, CJB111.

a) Phylogenetic tree of whole-genome sequenced GenBank isolates that encode the C-terminal 225 amino acids of EssC. Subtype I strains (example strain CJB111; n = 46) are highlighted in green, subtype II strains (example strain 2603V/R; n = 15) are highlighted in blue, subtype III strains (example strain CNCTC 10/84; n = 5) are highlighted in red, and subtype IV strains (example strain COH1; n = 14) are highlighted in yellow. b) Distribution of GBS T7SS subtypes based on EssC C-terminus in whole-genome sequenced GBS isolates that encode T7SS (n = 80). c) Diagram of the T7SS locus in CJB111 (roughly to scale; accession CP063198.2). Genes in purple encode WXG100 or WXG100-like proteins, gene in teal encodes a LXG domain-containing protein, and gene in maroon encodes a DUF4176 domain-containing protein. Genes in various shades of gray are either annotated as hypothetical or do not have a predicted function. Arrows with patterns indicate T7SS subtype-specific genes that exhibit little to no homology to those present in other GBS T7SS subtypes. Putative core genes of the operon are esaA through essC.