9Q6B | pdb_00009q6b

Cryo-electron microscopy structure of PfRIPR bound to monoclonal antibodies RP.093, RP.073 and RP.063

• PDB DOI: https://doi.org/10.2210/pdb9Q6B/pdb
• EM Map EMD-72265: EMDB EMDataResource

• Classification: IMMUNE SYSTEM
• Organism(s): Mus musculus, Plasmodium falciparum 3D7
• Expression System: Homo sapiens, Drosophila melanogaster
• Mutation(s): No 


• Deposited: 2025-08-21 Released: 2026-06-24 
• Deposition Author(s): Barrett, J.R., Ward, A.B.
• Funding Organization(s): Bill & Melinda Gates Foundation

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 2.97 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Analysis of monoclonal antibodies against the malaria invasion complex protein RIPR reveals the structural basis for synergistic antibody protection.

Williams, B.G., Barrett, J.R., Scott, J.B., Rigby, C.A., Cagiada, M., Quinkert, D., McHugh, K., Huhn, A., Burnap, S.A., Gourjault, C., Byrne, F., Raghavan, S.S.R., Rodrigues, A., Bergamaschi, L., Balzarotti, B., Watson, S., Miller, N., King, L.D.W., Donnellan, F.R., Gladstone, C.A., Paterson, J., Scalabrino, S., Silk, S.E., Salkeld, J., Minassian, A.M., Skinner, K., Struwe, W.B., Deane, C.M., Reece, S.T., Ward, A.B., Draper, S.J.

(2026) Immunity 

• PubMed: 42285102 
• DOI: https://doi.org/10.1016/j.immuni.2026.05.012
• Primary Citation Related Structures: 
  9Q69, 9Q6B, 9Q7C


• PubMed Abstract: 
  

  Plasmodium falciparum RH5-interacting protein (RIPR) is central to the essential PTRAMP-CSS-RIPR-CyRPA-RH5 (PCRCR) complex, a leading target of blood-stage malaria vaccines. However, mechanisms whereby anti-RIPR antibodies inhibit parasite invasion are poorly understood. We characterized 83 human IgG monoclonal antibodies (mAbs) from RIPR-vaccinated Kymouse platform mice. Single mAbs had minimal neutralizing activity; however, high-level synergistic inhibition was observed with pools of mAbs targeting the RIPR-tail region. Structural characterization and molecular dynamics simulations of RIPR-tail showed that mAbs targeting epidermal growth factor (EGF)-like domains 6-8 (RIPR ^{EGF (6-8)} ), but not RIPR ^{EGF (9-10)} or the C-terminal domain (RIPR ^CTD ), synergized to constrain the RIPR-tail conformation. The same antibodies dissociated PTRAMP-CSS from RIPR, thereby enabling anti-RIPR ^{EGF (9-10)-CTD} mAbs or anti-CSS single-domain Abs to bind and potentiate anti-RIPR ^{EGF (6-8)} IgG. Addition of these mAbs to IgG from humans immunized with the R78C (RIPR ^{EGF (7-8)} -CyRPA) candidate vaccine enhanced malaria growth inhibition. These data provide a framework to guide next-generation blood-stage malaria vaccine design.

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Organizational Affiliation: 
• Department of Paediatrics, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK; Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK.
Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA; Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK.
Kymab Ltd., a Sanofi Company, Babraham Research Campus, Cambridge, UK.
Department of Statistics, University of Oxford, Oxford, UK; Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
Department of Paediatrics, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK.
Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK; Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK.
Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA.
Department of Paediatrics, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK; Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK.
Department of Statistics, University of Oxford, Oxford, UK.
Department of Paediatrics, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK; Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK. Electronic address: [e-mail].

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 7-mer - A2B1C1D1E1F1 Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Hetero 7-mer - A6B1 

Biological assembly 1 assigned by authors and generated by (software)

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 197.63 kDa 
• Atom Count: 6,505 
• Modeled Residue Count: 838 
• Deposited Residue Count: 1,746 
• Unique protein chains: 7

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
RP.093 Heavy Chain	A	118	Mus musculus	Mutation(s): 0

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
RP.093 Light Chain	B	106	Mus musculus	Mutation(s): 0

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
RP.073 Heavy Chain	C	116	Mus musculus	Mutation(s): 0

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details	Image
RP.073 Light Chain	D	108	Mus musculus	Mutation(s): 0

Entity ID: 5
Molecule	Chains	Sequence Length	Organism	Details	Image
RP.063 Heavy Chain	E	120	Mus musculus	Mutation(s): 0

Entity ID: 6
Molecule	Chains	Sequence Length	Organism	Details	Image
RP.063 Light Chain	F	108	Mus musculus	Mutation(s): 0

Entity ID: 7
Molecule	Chains	Sequence Length	Organism	Details	Image
Rh5-interacting protein	G	1,070	Plasmodium falciparum 3D7	Mutation(s): 0  Gene Names: RIPR, PFC1045C, PF3D7_0323400
UniProt
Find proteins for O97302 (Plasmodium falciparum (isolate 3D7)) Explore O97302  Go to UniProtKB:  O97302

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 2.97 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
MODEL REFINEMENT	PHENIX	1.21.2_5419
RECONSTRUCTION	cryoSPARC

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-06-24 
Deposition Author(s): Barrett, J.R., Ward, A.B.

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Funding Organization	Location	Grant Number
Bill & Melinda Gates Foundation	United States	--

Revision History  

• Version 1.0: 2026-06-24
  Type: Initial release