Complement C5

Complement C5 (CC5) is the fifth component of the complement system. The complement system is part of the innate immune system. CC5 is composed of α chain (C5a) and β chain (C5b). Proteoplytic degradation of CC5 produces anaphylatoxin which is a mediator of local inflammatory process. The C terminal domain of CC5 (residues 1530-1676) is homologous to a domain in netrins and is named C345C. Activation of CC5 by C5 convertase initiates the assembly of the C5 to C9 components into the membrane attack complex.

Function

Disease

Mutations in CC5 cause a deficiency leading to severe recurrent infections and are linked to liver fibrosis and rheumatoid arthritis.

Relevance

Structural highlights