Complement component 5

1CFA, 1KJS, 1XWE, 3CU7, 3HQA, 3HQB, 3KLS, 3KM9, 3PRX, 3PVM, 4A5W, 4E0S, 4P39, 4UU9, 5I5K, 5HCE, 5HCC, 5HCD72715139ENSG00000106804ENSMUSG00000026874P01031P06684NM_001735NM_001317163NM_001317164NM_010406NP_001304092NP_001304093NP_001726NP_034536Complement component 5 is a protein that in humans is encoded by the C5 gene.1cfa: SOLUTION STRUCTURE OF A SEMI-SYNTHETIC C5A RECEPTOR ANTAGONIST AT PH 5.2, 303K, NMR, 20 STRUCTURES1kjs: NMR SOLUTION STRUCTURE OF C5A AT PH 5.2, 303K, 20 STRUCTURES1xwe: NMR Structure of C345C (NTR) domain of C5 of complement Complement component 5 is a protein that in humans is encoded by the C5 gene. Complement component 5 is involved in the complement system. It is cleaved into C5a and C5b: Deficiency is thought to cause Leiner's disease. Complement component 5 is the fifth component of complement, which plays an important role in inflammatory and cell killing processes. This protein is composed of alpha and beta polypeptide chains that are linked by a disulfide bridge. An activation peptide, C5a, which is an anaphylatoxin that possesses potent spasmogenic and chemotactic activity, is derived from the alpha polypeptide via cleavage with a C5-convertase. The C5b macromolecular cleavage product can form a complex with the C6 complement component, and this complex is the basis for formation of the membrane attack complex, which includes additional complement components. Mutations in this gene cause complement component 5 deficiency, a disease where patients show a propensity for severe recurrent infections. Defects in this gene have also been linked to a susceptibility to liver fibrosis and to rheumatoid arthritis. The drug eculizumab (trade name Soliris) prevents cleavage of C5 into C5a and C5b. This article incorporates text from the United States National Library of Medicine, which is in the public domain.