C5 deficiency

Gene Information


HUGO name: C5


  • complement component 5
  • Complement C5 precursor


Reference sequences

Chromosomal location


Protein Information


Protein function:

Activation of C5 by a C5 convertase initiates the spontaneous assembly of the late complement components, C5-C9, into the Membrane Attack Complex (MAC). C5b has a transient binding site for C6. The C5b-C6 complex is the foundation upon which the lytic complex is assembled.


C5 precursor is first processed by the removal of 4 basic residues, forming two chains, beta & alpha, linked by a disulfide bond. C5 convertase activates C5 by cleaving the alpha chain, releasing C5a anaphylatoxin & generating C5b (beta chain + alpha' chain).


Ref.3 sequence differs from that shown from position 855 onward due to the presence of an Alu repeat.

Structures (PDB)

1KJS NMR Solution Structure Of C5A At pH 5.2, 303K, 20 Structures
1CFA Solution Structure Of A Semi-Synthetic C5A Receptor Antagonist At pH 5.2, 303K, NMR, 20 Structures


Anaphylatoxin-like domain: 698-732

    Other features

    Signal peptide: 1-18

      Complement c5 beta chain: 19-673

        Propeptide: 674-677

          Complement c5 alpha chain: 678-1676

            Released active peptide C5a anaphylatoxin: 678-751

              C5b (alpha'): 752-1676

                Disulfide bond: 698-724

                  Disulfide bond: 699-731

                    Disulfide bond: 711-732

                      N-linked (glcnac...) glycosylation site: 741

                        N-linked (glcnac...) glycosylation site: 911

                          N-linked (glcnac...) glycosylation site: 1115

                            N-linked (glcnac...) glycosylation site: 1630

                              Other related resourses:


                              Expression pattern for human

                              Tissue Expression (%) Clones
                              corresponding non cancerous liver tissue 27.80 16:13909
                              germ cell, yolk sac 21.40 1:1129
                              lung epithelial cells tissue nos 359-368 5.53 1:4366
                              bone marrow stroma 4.53 1:5331
                              human skeletal muscle 4.50 2:10746
                              liver 3.71 4:26031
                              hypothalamus 3.68 1:6565
                              hepatocellular carcinoma 3.40 2:14226
                              spleen 3.34 1:7229
                              kidney, pooled 3.26 1:7404