2XRC

Human complement factor I

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.69 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.200 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history. 

Literature

Structural Basis for Complement Factor I Control and its Disease-Associated Sequence Polymorphisms.

Roversi, P., Johnson, S., Caesar, J.J., Mclean, F., Leath, K.J., Tsiftsoglou, S.A., Morgan, B.P., Harris, C.L., Sim, R.B., Lea, S.M.

(2011) Proc.Natl.Acad.Sci.USA 108: 12839

  • DOI: 10.1073/pnas.1102167108

  • PubMed Abstract: 

    • The complement system is a key component of innate and adaptive immune responses. Complement regulation is critical for prevention and control of disease. We have determined the crystal structure of the complement regulatory enzyme human factor I (fI ...

    The complement system is a key component of innate and adaptive immune responses. Complement regulation is critical for prevention and control of disease. We have determined the crystal structure of the complement regulatory enzyme human factor I (fI). FI is in a proteolytically inactive form, demonstrating that it circulates in a zymogen-like state despite being fully processed to the mature sequence. Mapping of functional data from mutants of fI onto the structure suggests that this inactive form is maintained by the noncatalytic heavy-chain allosterically modulating activity of the light chain. Once the ternary complex of fI, a cofactor and a substrate is formed, the allosteric inhibition is released, and fI is oriented for cleavage. In addition to explaining how circulating fI is limited to cleaving only C3b/C4b, our model explains the molecular basis of disease-associated polymorphisms in fI and its cofactors.

    Organizational Affiliation: 

    Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HUMAN COMPLEMENT FACTOR I
A, B, C, D
565Homo sapiensGene Names: CFI (IF)
EC: 3.4.21.45
Find proteins for P05156 (Homo sapiens)
Go to Gene View: CFI
Go to UniProtKB:  P05156
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA
Download SDF File 
Download CCD File 
A, B, C, D
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
NAG
Query on NAG
Download SDF File 
Download CCD File 
A, B, C, D
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.69 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.200 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 71.317α = 89.98
b = 234.721β = 90.18
c = 40.300γ = 90.03
Software Package:
Software NamePurpose
XDSdata reduction
REFMACrefinement
SCALAdata scaling
PHASERphasing

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-07-13
    Type: Initial release
  • Version 1.1: 2011-08-17
    Type: Database references