7PI6 image
Entry Detail
PDB ID:
7PI6
Keywords:
Title:
Trypanosoma brucei ISG65 bound to human complement C3d
Biological Source:
PDB Version:
Deposition Date:
2021-08-19
Release Date:
2022-07-27
Method Details:
Experimental Method:
Resolution:
2.60 Å
R-Value Free:
0.31
R-Value Work:
0.26
R-Value Observed:
0.26
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:65 kDa invariant surface glycoprotein
Chain IDs:A, C
Chain Length:400
Number of Molecules:2
Biological Source:Trypanosoma brucei brucei (strain 927/4 GUTat10.1)
Polymer Type:polypeptide(L)
Description:Complement C3dg fragment
Chain IDs:B, D
Chain Length:293
Number of Molecules:2
Biological Source:Homo sapiens
Primary Citation
Invariant surface glycoprotein 65 of Trypanosoma brucei is a complement C3 receptor.
Nat Commun 13 5085 5085 (2022)
PMID: 36038546 DOI: 10.1038/s41467-022-32728-9

Abstact

African trypanosomes are extracellular pathogens of mammals and are exposed to the adaptive and innate immune systems. Trypanosomes evade the adaptive immune response through antigenic variation, but little is known about how they interact with components of the innate immune response, including complement. Here we demonstrate that an invariant surface glycoprotein, ISG65, is a receptor for complement component 3 (C3). We show how ISG65 binds to the thioester domain of C3b. We also show that C3 contributes to control of trypanosomes during early infection in a mouse model and provide evidence that ISG65 is involved in reducing trypanosome susceptibility to C3-mediated clearance. Deposition of C3b on pathogen surfaces, such as trypanosomes, is a central point in activation of the complement system. In ISG65, trypanosomes have evolved a C3 receptor which diminishes the downstream effects of C3 deposition on the control of infection.

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