| Primary Identifier | IPR041909 | Type | Homologous_superfamily |
| Short Name | Sbi_C3_db_domIV |
| description | This superfamily includes the immunoglobulin-binding protein Sbi domain IV (Sbi-IV) which binds the central complement protein C3. Sbi-IV interacts with Sbi-III to induce a consumption of complement via alternative pathway activation []. When not interacting with Sbi-III, Sbi-IV inhibits the alternative pathway without complement consumption. Sbi-IV structurally comprises a three-helix bundle [].Sbi-IV is similar to Efb-C and Ehp [, , ]. Sbi-IV binds to the thioester-containing domain of native C3. The interaction between Sbi-IV and C3, in the presence of domain III, results in the formation of a covalent Sbi-III-IV-C3 adduct followed by futile fluid phase consumption of C3 []. |
