6RQJ

Structure of human complement C5 complexed with tick inhibitors OmCI, RaCI1 and CirpT1


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.5 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

An inhibitor of complement C5 provides structural insights into activation.

Reichhardt, M.P.Johnson, S.Tang, T.Morgan, T.Tebeka, N.Popitsch, N.Deme, J.C.Jore, M.M.Lea, S.M.

(2019) Proc.Natl.Acad.Sci.USA --: --

  • DOI: 10.1073/pnas.1909973116
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The complement system is a crucial part of innate immune defenses against invading pathogens. The blood-meal of the tick <i>Rhipicephalus pulchellus </i> lasts for days, and the tick must therefore rely on inhibitors to counter complement activation ...

    The complement system is a crucial part of innate immune defenses against invading pathogens. The blood-meal of the tick Rhipicephalus pulchellus lasts for days, and the tick must therefore rely on inhibitors to counter complement activation. We have identified a class of inhibitors from tick saliva, the CirpT family, and generated detailed structural data revealing their mechanism of action. We show direct binding of a CirpT to complement C5 and have determined the structure of the C5-CirpT complex by cryoelectron microscopy. This reveals an interaction with the peripheral macro globulin domain 4 (C5_MG4) of C5. To achieve higher resolution detail, the structure of the C5_MG4-CirpT complex was solved by X-ray crystallography (at 2.7 Å). We thus present the fold of the CirpT protein family, and provide detailed mechanistic insights into its inhibitory function. Analysis of the binding interface reveals a mechanism of C5 inhibition, and provides information to expand our biological understanding of the activation of C5, and thus the terminal complement pathway.


    Organizational Affiliation

    Sir William Dunn School of Pathology, University of Oxford, OX1 3RE Oxford, United Kingdom; susan.lea@path.ox.ac.uk.,Wellcome Centre for Human Genetics, University of Oxford, OX3 7BN Oxford, United Kingdom.,Sir William Dunn School of Pathology, University of Oxford, OX1 3RE Oxford, United Kingdom.,Central Oxford Structural Molecular Imaging Centre, University of Oxford, OX1 3RE Oxford, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Complement C5
A
999Homo sapiensMutation(s): 0 
Gene Names: C5 (CPAMD4)
Find proteins for P01031 (Homo sapiens)
Go to Gene View: C5
Go to UniProtKB:  P01031
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Complement inhibitor
C
165Ornithodoros moubataMutation(s): 2 
Gene Names: CI
Find proteins for Q5YD59 (Ornithodoros moubata)
Go to UniProtKB:  Q5YD59
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Rhipicephalus appendiculatus RaCI1
D
81Rhipicephalus appendiculatusMutation(s): 0 
Find proteins for A0A158RFT5 (Rhipicephalus appendiculatus)
Go to UniProtKB:  A0A158RFT5
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
Complement C5
B
655Homo sapiensMutation(s): 0 
Gene Names: C5 (CPAMD4)
Find proteins for P01031 (Homo sapiens)
Go to Gene View: C5
Go to UniProtKB:  P01031
Entity ID: 5
MoleculeChainsSequence LengthOrganismDetails
Putative 8.9 kDa family member
E
112Rhipicephalus pulchellusMutation(s): 0 
Find proteins for L7MB58 (Rhipicephalus pulchellus)
Go to UniProtKB:  L7MB58
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

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

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.5 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
Software Package:
Software NamePurpose
PHENIXrefinement
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Finnish Cultural FoundationFinland--
Wellcome TrustUnited Kingdom100298
Wellcome TrustUnited Kingdom201536
Wolfson FoundationUnited KingdomWL160052

Revision History 

  • Version 1.0: 2020-01-08
    Type: Initial release
  • Version 1.1: 2020-01-15
    Type: Source and taxonomy