Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 3-mer - ABC Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Hetero 3-mer -A2B 

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

Macromolecule Content

• Total Structure Weight: 118528.00 
• Atom Count: 8035 
• Residue Count: 1068 
• Unique protein chains: 3

4LEO

Crystal structure of anti-HER3 Fab RG7116 in complex with the extracellular domains of human Her3 (ERBB3)

• DOI: 10.2210/pdb4LEO/pdb

• Classification: Transferase/Immune System
• Organism(s): Homo sapiens
• Expression System: Cricetulus griseus


• Deposited: 2013-06-26 Released: 2013-07-10 
• Deposition Author(s): Schiller, C.B., Hopfner, K.P.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.64 Å
• R-Value Free: 0.258 
• R-Value Work: 0.228 

Literature

RG7116, a Therapeutic Antibody That Binds the Inactive HER3 Receptor and Is Optimized for Immune Effector Activation.

Mirschberger, C., Schiller, C.B., Schraml, M., Dimoudis, N., Friess, T., Gerdes, C.A., Reiff, U., Lifke, V., Hoelzlwimmer, G., Kolm, I., Hopfner, K.P., Niederfellner, G., Bossenmaier, B.

(2013) Cancer Res. 73: 5183-5194

• PubMed: 23780344 
• DOI: 10.1158/0008-5472.CAN-13-0099


• PubMed Abstract: 
  

The EGF receptor (EGFR) HER3 is emerging as an attractive cancer therapeutic target due to its central position in the HER receptor signaling network. HER3 amplifies phosphoinositide 3-kinase (PI3K)-driven tumorigenesis and its upregulation in response to other anti-HER therapies has been implicated in resistance to them. Here, we report the development and characterization of RG7116, a novel anti-HER3 monoclonal antibody (mAb) designed to block HER3 activation, downregulate HER3, and mediate enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) via glycoengineering of the Fc moiety. Biochemical studies and X-ray crystallography revealed that RG7116 bound potently and selectively to domain 1 of human HER3. Heregulin binding was prevented by RG7116 at concentrations more than 1 nmol/L as was nearly complete inhibition of HER3 heterodimerization and phosphorylation, thereby preventing downstream AKT phosphorylation. In vivo RG7116 treatment inhibited xenograft tumor growth up to 90% relative to controls in a manner accompanied by downregulation of cell surface HER3. RG7116 efficacy was further enhanced in combination with anti-EGFR (RG7160) or anti-HER2 (pertuzumab) mAbs. Furthermore, the ADCC potency of RG7116 was enhanced compared with the nonglycoengineered parental antibody, both in vitro and in orthotopic tumor xenograft models, where an increased median survival was documented. ADCC degree achieved in vitro correlated with HER3 expression levels on tumor cells. In summary, the combination of strong signaling inhibition and enhanced ADCC capability rendered RG7116 a highly potent HER3-targeting agent suitable for clinical development.

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Organizational Affiliation: 

Pharma Research and Early Development (pRED), Roche Diagnostics GmbH, Penzberg, Germany. [e-mail]

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
RG7116 Fab heavy chain	A	227	N/A	Mutation(s): 0
Protein Feature View is not available: No corresponding UniProt sequence found.

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details
RG7116 Fab light chain	B	220	N/A	Mutation(s): 0
Protein Feature View is not available: No corresponding UniProt sequence found.

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details
Receptor tyrosine-protein kinase erbB-3	C	621	Homo sapiens	Mutation(s): 0  Gene Names: ERBB3 (HER3) EC: 2.7.10.1
Find proteins for P21860 (Homo sapiens) Go to Gene View: ERBB3 Go to UniProtKB:  P21860

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
NAG	C	N-ACETYL-D-GLUCOSAMINE C8 H15 N O6 OVRNDRQMDRJTHS-FMDGEEDCSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.64 Å
• R-Value Free: 0.258 
• R-Value Work: 0.228 
• Space Group: P 1

Unit Cell:

Length (Å)	Angle (°)
a = 54.458	α = 97.64
b = 59.359	β = 106.85
c = 103.661	γ = 96.83

Software Package:

Software Name	Purpose
PHASER	phasing
XDS	data reduction
XDS	data scaling
PHENIX	refinement

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2013-06-26 
• Released Date: 2013-07-10 
• Deposition Author(s): Schiller, C.B., Hopfner, K.P.

Revision History 

• Version 1.0: 2013-07-10
  Type: Initial release
• Version 1.1: 2013-08-28
  Type: Database references
• Version 1.2: 2017-11-15
  Type: Advisory, Refinement description
• Version 1.3: 2018-01-24
  Type: Structure summary