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2i6s
From Proteopedia
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(New page: 200px<br /> <applet load="2i6s" size="450" color="white" frame="true" align="right" spinBox="true" caption="2i6s, resolution 2.700Å" /> '''Complement compone...)
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Revision as of 20:35, 12 November 2007
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Complement component C2a
Contents |
Overview
C2a provides the catalytic center to the convertase complexes of the, classical and lectin-binding pathways of complement activation. We, determined two crystal structures of full-length C2a, with and without a, pseudo ligand bound. Both structures reveal a near-active conformation of, the catalytic center of the serine protease domains, while the von, Willebrand factor A-type domains display an intermediate activation state, of helix alpha7 with an open, activated metal-ion-dependent adhesion site., The open adhesion site likely serves to enhance the affinity for the, ligand C4b, similar to "inside-out" signaling in integrins. Surprisingly, the N-terminal residues of C2a are buried in a crevice near helix alpha7, indicative of a structural switch between C2 and C2a. Extended loops on, the protease domain possibly envelop the protruding anaphylatoxin domain, of the substrate C3. Together with a putative substrate-induced completion, of the oxyanion hole, this may contribute to the high substrate, specificity of the convertases.
Disease
Known diseases associated with this structure: C2 deficiency OMIM:[217000], Macular degeneration, age-related, reduced risk of OMIM:[217000]
About this Structure
2I6S is a Single protein structure of sequence from Homo sapiens with NAG as ligand. Active as Classical-complement-pathway C3/C5 convertase, with EC number 3.4.21.43 Full crystallographic information is available from OCA.
Reference
Structure of complement component C2A: implications for convertase formation and substrate binding., Milder FJ, Raaijmakers HC, Vandeputte MD, Schouten A, Huizinga EG, Romijn RA, Hemrika W, Roos A, Daha MR, Gros P, Structure. 2006 Oct;14(10):1587-97. PMID:17027507
Page seeded by OCA on Mon Nov 12 22:41:54 2007
Categories: Classical-complement-pathway C3/C5 convertase | Homo sapiens | Single protein | Daha, M.R. | Gros, P. | Hemrika, W. | Huizinga, E.G. | Milder, F.J. | Raaijmakers, H.C.A. | Romijn, R.A. | Roos, A. | Schouten, A. | Vandeputte, D.A.A. | NAG | Serine protease domain | Von willebrand factor-a domain
