Figure 5

Core and accessory genomes of ΦCP9O, ΦCP13O, ΦCP26F, and ΦCP34O. A) Shared and unique genes based on sequence similarity clustering of genes belonging to pfam families or clusters of orthologous groups (COGs) as classified by IMG and shown in Figure 4. Clustering was performed using CD-HIT with a 40% sequence similarity cutoff as described in the text. Each circle of the Venn diagram contains all genes belonging to the host-infectivity group; intersections represent shared genes. Numbers of outside of parentheses indicate total number of ORFs, numbers inside parentheses indicate numbers of genes belonging to known pfam families and COGs respectively. B) Distributions of pairwise sequence similarity for the 17 core pfam families shown in (a). Within each pfam, all possible pairwise similarities were calculated for each gene from the four phages compared in (a) and ΦCP39O. Genes belonging to the five pfam families shown in grey were defined as a variable core genome and boxes in white defined as a conserved core genome.