3HS0

Cobra Venom Factor (CVF) in complex with human factor B

Summary for 3HS0

• Entry DOI: 10.2210/pdb3hs0/pdb
• Related: 3HRZ
• Descriptor: Cobra venom factor, Complement factor B, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (8 entities in total)
• Functional Keywords: serine protease, glycosilated, multi-domain, complement system, convertase, complement alternate pathway, complement pathway, disulfide bond, glycoprotein, immune response, inflammatory response, innate immunity, secreted, thioester bond, cleavage on pair of basic residues, glycation, hydrolase, protease, sushi, zymogen, immune system
• Biological source: Homo sapiens (human); More
• Cellular location: Secreted: Q91132 Q91132 Q91132 P00751
• Total number of polymer chains: 8
• Total formula weight: 452138.39

Authors

Janssen, B.J.C.,Gomes, L.,Koning, R.I.,Svergun, D.I.,Koster, A.J.,Fritzinger, D.C.,Vogel, C.-W.,Gros, P. (deposition date: 2009-06-10, release date: 2009-07-07, Last modification date: 2024-10-30)

Primary citation

Janssen, B.J.,Gomes, L.,Koning, R.I.,Svergun, D.I.,Koster, A.J.,Fritzinger, D.C.,Vogel, C.W.,Gros, P.
Insights into complement convertase formation based on the structure of the factor B-cobra venom factor complex
Embo J., 28:2469-2478, 2009

PubMed Abstract: Immune protection by the complement system critically depends on assembly of C3 convertases on the surface of pathogens and altered host cells. These short-lived protease complexes are formed through pro-convertases, which for the alternative pathway consist of the complement component C3b and the pro-enzyme factor B (FB). Here, we present the crystal structure at 2.2-A resolution, small-angle X-ray scattering and electron microscopy (EM) data of the pro-convertase formed by human FB and cobra venom factor (CVF), a potent homologue of C3b that generates more stable convertases. FB is loaded onto CVF through its pro-peptide Ba segment by specific contacts, which explain the specificity for the homologous C3b over the native C3 and inactive products iC3b and C3c. The protease segment Bb binds the carboxy terminus of CVF through the metal-ion dependent adhesion site of the Von Willebrand factor A-type domain. A possible dynamic equilibrium between a 'loading' and 'activation' state of the pro-convertase may explain the observed difference between the crystal structure of CVFB and the EM structure of C3bB. These insights into formation of convertases provide a basis for further development of complement therapeutics.

PubMed: 19574954
DOI: 10.1038/emboj.2009.184

Experimental method

X-RAY DIFFRACTION (3 Å)