6EHG

complement component C3b in complex with a nanobody


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.65 Å

wwPDB Validation   3D Report Full Report



Literature

A potent complement factor C3-specific nanobody inhibiting multiple functions in the alternative pathway of human and murine complement.

Jensen, R.K.Pihl, R.Gadeberg, T.A.F.Jensen, J.K.Andersen, K.R.Thiel, S.Laursen, N.S.Andersen, G.R.

(2018) J Biol Chem 293: 6269-6281

  • DOI: 10.1074/jbc.RA117.001179
  • Primary Citation of Related Structures:  
    6EHG

  • PubMed Abstract: 
  • The complement system is a complex, carefully regulated proteolytic cascade for which suppression of aberrant activation is of increasing clinical relevance, and inhibition of the complement alternative pathway is a subject of intense research. Here, we ...

    The complement system is a complex, carefully regulated proteolytic cascade for which suppression of aberrant activation is of increasing clinical relevance, and inhibition of the complement alternative pathway is a subject of intense research. Here, we describe the nanobody hC3Nb1 that binds to multiple functional states of C3 with subnanomolar affinity. The nanobody causes a complete shutdown of alternative pathway activity in human and murine serum when present in concentrations comparable with that of C3, and hC3Nb1 is shown to prevent proconvertase assembly, as well as binding of the C3 substrate to C3 convertases. Our crystal structure of the C3b-hC3Nb1 complex and functional experiments demonstrate that proconvertase formation is blocked by steric hindrance between the nanobody and an Asn-linked glycan on complement factor B. In addition, hC3Nb1 is shown to prevent factor H binding to C3b, rationalizing its inhibition of factor I activity. Our results identify hC3Nb1 as a versatile, inexpensive, and powerful inhibitor of the alternative pathway in both human and murine in vitro model systems of complement activation.


    Organizational Affiliation

    From the Departments of Molecular Biology and Genetics and gra@mbg.au.dk.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Complement C3 A643Homo sapiensMutation(s): 0 
Gene Names: C3CPAMD1
Find proteins for P01024 (Homo sapiens)
Explore P01024 
Go to UniProtKB:  P01024
NIH Common Fund Data Resources
PHAROS:  P01024
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Complement C3 B915Homo sapiensMutation(s): 0 
Gene Names: C3CPAMD1
Find proteins for P01024 (Homo sapiens)
Explore P01024 
Go to UniProtKB:  P01024
NIH Common Fund Data Resources
PHAROS:  P01024
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
hC3Nb1 C130Lama glamaMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Oligosaccharides

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Entity ID: 4
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
D
3 N-Glycosylation Oligosaccharides Interaction
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download Ideal Coordinates CCD File 
B
2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.65 Å
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 255.31α = 90
b = 64.88β = 90
c = 144.72γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2018-02-14
    Type: Initial release
  • Version 1.1: 2018-03-14
    Changes: Database references
  • Version 1.2: 2018-05-09
    Changes: Data collection, Database references
  • Version 1.3: 2019-10-16
    Changes: Data collection
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Structure summary