2XWJ

Crystal Structure of Complement C3b in Complex with Factor B

Summary for 2XWJ

• Entry DOI: 10.2210/pdb2xwj/pdb
• Related: 1C3D 1DLE 1GHQ 1Q0P 1RRK 1RS0 1RTK 1W2S 2A73 2A74 2HR0 2WII 2WIN 2WY7 2WY8 2XQW 2XW9 2XWA 2XWB
• Descriptor: COMPLEMENT C3 BETA CHAIN, COMPLEMENT C3 ALPHA CHAIN, COMPLEMENT FACTOR B, ... (6 entities in total)
• Functional Keywords: immune system, pro-convertase, hydrolase, serine protease, conformational changes, alternative pathway
• Biological source: HOMO SAPIENS (HUMAN); More
• Cellular location: Secreted: P01024 P01024 P00751
• Total number of polymer chains: 12
• Total formula weight: 1036653.74

Authors

Forneris, F.,Ricklin, D.,Wu, J.,Tzekou, A.,Wallace, R.S.,Lambris, J.D.,Gros, P. (deposition date: 2010-11-04, release date: 2011-01-12, Last modification date: 2024-11-06)

Primary citation

Forneris, F.,Ricklin, D.,Wu, J.,Tzekou, A.,Wallace, R.S.,Lambris, J.D.,Gros, P.
Structures of C3B in Complex with Factors B and D Give Insight Into Complement Convertase Formation.
Science, 330:1816-, 2010

PubMed Abstract: Activation of the complement cascade induces inflammatory responses and marks cells for immune clearance. In the central complement-amplification step, a complex consisting of surface-bound C3b and factor B is cleaved by factor D to generate active convertases on targeted surfaces. We present crystal structures of the pro-convertase C3bB at 4 angstrom resolution and its complex with factor D at 3.5 angstrom resolution. Our data show how factor B binding to C3b forms an open "activation" state of C3bB. Factor D specifically binds the open conformation of factor B through a site distant from the catalytic center and is activated by the substrate, which displaces factor D's self-inhibitory loop. This concerted proteolytic mechanism, which is cofactor-dependent and substrate-induced, restricts complement amplification to C3b-tagged target cells.

PubMed: 21205667
DOI: 10.1126/SCIENCE.1195821

Experimental method

X-RAY DIFFRACTION (4 Å)