2a73
From Proteopedia
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Human Complement Component C3
Contents |
Overview
The mammalian complement system is a phylogenetically ancient cascade, system that has a major role in innate and adaptive immunity. Activation, of component C3 (1,641 residues) is central to the three complement, pathways and results in inflammation and elimination of self and non-self, targets. Here we present crystal structures of native C3 and its final, major proteolytic fragment C3c. The structures reveal thirteen domains, nine of which were unpredicted, and suggest that the proteins of the, alpha2-macroglobulin family evolved from a core of eight homologous, domains. A double mechanism prevents hydrolysis of the thioester group, essential for covalent attachment of activated C3 to target surfaces., Marked conformational changes in the alpha-chain, including movement of a, critical interaction site through a ring formed by the domains of the, beta-chain, indicate an unprecedented, conformation-dependent mechanism of, activation, regulation and biological function of C3.
Disease
Known diseases associated with this structure: C3 deficiency OMIM:[120700], Macular degeneration, age-related, 9 OMIM:[120700]
About this Structure
2A73 is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Structures of complement component C3 provide insights into the function and evolution of immunity., Janssen BJ, Huizinga EG, Raaijmakers HC, Roos A, Daha MR, Nilsson-Ekdahl K, Nilsson B, Gros P, Nature. 2005 Sep 22;437(7058):505-11. PMID:16177781
Page seeded by OCA on Mon Nov 12 20:46:49 2007
