Analyses of predicted attC sites. (A) Multiple alignment of attC sites, focusing on the core sites R”, L”, L’, and R’. The protruding G (red asterisk) is highlighted. (B) shows the predicted structures of the attC sites identified in T. denticola (denti7), T. phagedenis (brenna1), and T. succinifaciens (succini1). We selected the most representative attC sites for demonstration purposes: at least 33 attC sites identified in T. denticola share 90% sequence identify over 55 bp with denti7, and in the T. succinifaciens genome, another five attC sites share high sequence similarity (with 92–96% sequence identity) with succini1.