1q0p
From Proteopedia
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| , resolution 1.8Å | |||||||
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| Ligands: | |||||||
| Gene: | BF (Homo sapiens) | ||||||
| Activity: | Alternative-complement-pathway C3/C5 convertase, with EC number 3.4.21.47 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
A domain of Factor B
Contents |
Overview
Complement factor B is a 90 kDa protein consisting of three domains: a three-module complement control protein, a von Willebrand factor A domain, and a C-terminal serine protease (SP) domain that adopts a default inactive (zymogen) conformation. The interaction between factor B and pathogen-bound C3b is mediated by its A domain, triggering a conformational change in factor B that ultimately creates the "C3 convertase" of the alternative complement pathway. We report the crystal structure of the A domain from factor B and show that it contains an integrin-like MIDAS motif that adopts the "open" conformation typical of integrin-ligand complexes, with an acidic residue (provided by a fortuitous crystal contact) completing the coordination of the metal ion. Modeling studies indicate that the factor B A domain can also adopt the closed conformation, supporting the hypothesis that an "integrin-like switch" is conserved in complement proteins and perhaps in 60 other A domains found within the human proteome.
Disease
Known diseases associated with this structure: Macular degeneration, age-related, reduced risk of OMIM:[138470]
About this Structure
1Q0P is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystal structure of the A domain from complement factor B reveals an integrin-like open conformation., Bhattacharya AA, Lupher ML Jr, Staunton DE, Liddington RC, Structure. 2004 Mar;12(3):371-8. PMID:15016353
Page seeded by OCA on Thu Mar 20 13:31:28 2008
