Additional file 5 of CrfP, a fratricide protein, contributes to natural transformation in Streptococcus suis

Additional file 5. Phylogenetic analysis of CrfP homologous proteins from Streptococcus species. (A) Evolutionary relationship between murein hydrolases from different species. Three branches were formed based on amino acid differences, and the diverse serotype SS belonged to the same group and was far from the other species. A neighbour-joining tree (bootstrap n = 1000; Poisson correction) was constructed based on a ClustalW alignment of the amino acid sequences using MEGA software version 5.0. (B) CrfP protein from different S. suis strains showed high amino acid sequence similarity. The green background indicates similarity >75%, and the blue background indicates similarity >100%.