The high relatedness of these tail morphogenesis proteins between known type IV pili phages DLP4 and AXL1 with Bosa and Xp12 (Fig. 6), specifically with AXL1 gp44 that contains an Mtd_N domain involved in receptor specificity, suggests that these phages may also use the type IV pilus virulence factor as their receptor for host infection. Here, SGCG is linked to infection.