Publication Date:
2011-01-06
Description:
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.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3087196/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3087196/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Forneris, Federico -- Ricklin, Daniel -- Wu, Jin -- Tzekou, Apostolia -- Wallace, Rachel S -- Lambris, John D -- Gros, Piet -- AI030040/AI/NIAID NIH HHS/ -- AI068730/AI/NIAID NIH HHS/ -- AI072106/AI/NIAID NIH HHS/ -- GM062134/GM/NIGMS NIH HHS/ -- P01 AI068730/AI/NIAID NIH HHS/ -- P01 AI068730-04/AI/NIAID NIH HHS/ -- R01 AI030040/AI/NIAID NIH HHS/ -- R01 AI030040-14/AI/NIAID NIH HHS/ -- R01 AI072106/AI/NIAID NIH HHS/ -- R01 AI072106-04/AI/NIAID NIH HHS/ -- R01 GM062134/GM/NIGMS NIH HHS/ -- R01 GM062134-08/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2010 Dec 24;330(6012):1816-20. doi: 10.1126/science.1195821.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21205667" target="_blank"〉PubMed〈/a〉
Keywords:
Binding Sites
;
Catalytic Domain
;
Complement C3 Convertase, Alternative Pathway/*chemistry/metabolism
;
Complement C3b/*chemistry/metabolism
;
Complement Factor B/*chemistry/metabolism
;
Complement Factor D/*chemistry/metabolism
;
Complement Pathway, Alternative
;
Crystallography, X-Ray
;
Humans
;
Models, Molecular
;
Mutant Proteins/chemistry
;
Protein Binding
;
Protein Conformation
;
Protein Structure, Tertiary
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
