5O35

Structure of complement proteins complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 4.2 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.216 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Regulator-dependent mechanisms of C3b processing by factor I allow differentiation of immune responses.

Xue, X.Wu, J.Ricklin, D.Forneris, F.Di Crescenzio, P.Schmidt, C.Q.Granneman, J.Sharp, T.H.Lambris, J.D.Gros, P.

(2017) Nat. Struct. Mol. Biol. 24: 643-651

  • DOI: 10.1038/nsmb.3427
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The complement system labels microbes and host debris for clearance. Degradation of surface-bound C3b is pivotal to direct immune responses and protect host cells. How the serine protease factor I (FI), assisted by regulators, cleaves either two or t ...

    The complement system labels microbes and host debris for clearance. Degradation of surface-bound C3b is pivotal to direct immune responses and protect host cells. How the serine protease factor I (FI), assisted by regulators, cleaves either two or three distant peptide bonds in the CUB domain of C3b remains unclear. We present a crystal structure of C3b in complex with FI and regulator factor H (FH; domains 1-4 with 19-20). FI binds C3b-FH between FH domains 2 and 3 and a reoriented C3b C-terminal domain and docks onto the first scissile bond, while stabilizing its catalytic domain for proteolytic activity. One cleavage in C3b does not affect its overall structure, whereas two cleavages unfold CUB and dislodge the thioester-containing domain (TED), affecting binding of regulators and thereby determining the number of cleavages. These data explain how FI generates late-stage opsonins iC3b or C3dg in a context-dependent manner, to react to foreign, danger or healthy self signals.


    Organizational Affiliation

    Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Complement C3
A
645Homo sapiensMutation(s): 0 
Gene Names: C3 (CPAMD1)
Find proteins for P01024 (Homo sapiens)
Go to Gene View: C3
Go to UniProtKB:  P01024
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Complement C3
B
915Homo sapiensMutation(s): 0 
Gene Names: C3 (CPAMD1)
Find proteins for P01024 (Homo sapiens)
Go to Gene View: C3
Go to UniProtKB:  P01024
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Complement factor H,Complement factor H
C
383Homo sapiensMutation(s): 0 
Gene Names: CFH (HF, HF1, HF2)
Find proteins for P08603 (Homo sapiens)
Go to Gene View: CFH
Go to UniProtKB:  P08603
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download SDF File 
Download CCD File 
B
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 4.2 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.216 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 142.900α = 90.00
b = 142.900β = 90.00
c = 312.721γ = 120.00
Software Package:
Software NamePurpose
XDSdata reduction
Aimlessdata scaling
PHENIXrefinement
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of HealthUnited StatesR01AI030040-16
NWONetherlandsSpinoza 01.80.104.00
European Research CouncilNetherlandsAdG 233229

Revision History 

  • Version 1.0: 2017-06-28
    Type: Initial release
  • Version 1.1: 2017-07-12
    Type: Database references
  • Version 1.2: 2017-08-16
    Type: Database references
  • Version 1.3: 2018-01-31
    Type: Author supporting evidence