| AD families | AD genes | Defense system | CLAN ID | Phages/MGEs | References | Description |
|---|---|---|---|---|---|---|
| APIS179 | Ddrb | restriction-modification (RM) | CLAN063 | Escherichia phage P1 | PMID:28509398 | It's included in the P1 restriction system. The presence of DdrB results in reduced antirestriction activity, presumably by negatively affecting DarB but the mechanism is not known. |