Phylogenetic analyses and similarity of the HE genes from different T4-related phages. ϕpp2 is a Vibrio phage isolated in this study. PEG numbers without dash are Enterobacteria phage T4. The homing endonucleases are named with gene product numbers followed by the dash lines for the hosts of the phages: Enterobacteria phages include RB14, RB16, RB32, RB51, JS10, and JSE; Aeromonas phages, Aeh1, 25 and 65; PBCV-1 is Paramecium bursaria Chlorella virus 1; and Vibrio phage ICP1. (A) Rooted phylogenetic tree for the homing endonucleases of Vibrio and T4-like phages by PROTDIST-neighbor joining method; the amino acid sequences were aligned with BLOSUM62 matrix, gap penalty = 8 and extension penalty = 2. (B) Bootstrap analysis for the Mob-type HEs of the Vibrio phages against T4 phages. The bootstrap values of percentages in 1000 replicates are placed on the branch for the nodes defining each monophyletic clade. The scale bars represent distance length. (C) H-N-H alignment of three HE genes from ϕpp2 with T4 mobE and ICP1 ORF28 (a phage in Vibrio cholerae).