4HW5

Crystal Structure of the Human C3a anaphylatoxin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.244 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Human C3a and C3a desArg anaphylatoxins have conserved structures, in contrast to C5a and C5a desArg.

Bajic, G.Yatime, L.Klos, A.Andersen, G.R.

(2013) Protein Sci. 22: 204-212

  • DOI: 10.1002/pro.2200
  • Primary Citation of Related Structures:  4HWJ

  • PubMed Abstract: 
  • Complement is a part of innate immunity that has a critical role in the protection against microbial infections, bridges the innate with the adaptive immunity and initiates inflammation. Activation of the complement, by specific recognition of molecu ...

    Complement is a part of innate immunity that has a critical role in the protection against microbial infections, bridges the innate with the adaptive immunity and initiates inflammation. Activation of the complement, by specific recognition of molecular patterns presented by an activator, for example, a pathogen cell, in the classical and lectin pathways or spontaneously in the alternative pathway, leads to the opsonization of the activator and the production of pro-inflammatory molecules such as the C3a anaphylatoxin. The biological function of this anaphylatoxin is regulated by carboxypeptidase B, a plasma protease that cleaves off the C-terminal arginine yielding C3a desArg, an inactive form. While functional assays demonstrate strikingly different physiological effects between C3a and C3a desArg, no structural information is available on the possible conformational differences between the two proteins. Here, we report a novel and simple expression and purification protocol for recombinant human C3a and C3a desArg anaphylatoxins, as well as their crystal structures at 2.3 and 2.6 Å, respectively. Structural analysis revealed no significant conformational differences between the two anaphylatoxins in contrast to what has been reported for C5a and C5a desArg. We compare the structures of different anaphylatoxins and discuss the relevance of their observed conformations to complement activation and binding of the anaphylatoxins to their cognate receptors.


    Organizational Affiliation

    Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus, Denmark.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Complement C3
A, B
83Homo sapiensGene Names: C3 (CPAMD1)
Find proteins for P01024 (Homo sapiens)
Go to Gene View: C3
Go to UniProtKB:  P01024
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.244 
  • Space Group: P 63
Unit Cell:
Length (Å)Angle (°)
a = 63.880α = 90.00
b = 63.880β = 90.00
c = 105.110γ = 120.00
Software Package:
Software NamePurpose
PHENIXrefinement
MxCuBEdata collection
XSCALEdata scaling
PHASERphasing
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-12-12
    Type: Initial release
  • Version 1.1: 2013-02-13
    Type: Database references