4 component system: The ATP-binding Cassette (ABC) Superfamily
| Q92LL2 | PUTATIVE IRON TRANSPORT SYSTEM MEMBRANE ABC TRANSPORTER PROTEIN aka SitD |
|---|---|
| Q92LL3 | PUTATIVE IRON TRANSPORT SYSTEM MEMBRANE ABC TRANSPORTER PROTEIN aka SitC |
| Q92LL4 | PUTATIVE IRON TRANSPORT ATP-BINDING ABC TRANSPORTER PROTEIN aka SitB |
| Q92LL5 | PUTATIVE IRON-BINDING PERIPLASMIC ABC TRANSPORTER PROTEIN aka SitA |