8Y9B | pdb_00008y9b

TcdB1 in complex with mini-binder

• PDB DOI: https://doi.org/10.2210/pdb8Y9B/pdb
• EM Map EMD-39072: EMDB EMDataResource

• Classification: TOXIN/DE NOVO PROTEIN
• Organism(s): Clostridioides difficile, synthetic construct
• Expression System: Bacillus subtilis, Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2024-02-06 Released: 2024-08-28 
• Deposition Author(s): Lv, X.C., Lu, P.L.
• Funding Organization(s): Ministry of Science and Technology (MoST, China), National Natural Science Foundation of China (NSFC)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.20 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Starting Models: in silico, experimental

Literature

De novo design of mini-protein binders broadly neutralizing Clostridioides difficile toxin B variants.

Lv, X., Zhang, Y., Sun, K., Yang, Q., Luo, J., Tao, L., Lu, P.

(2024) Nat Commun 15: 8521-8521

• PubMed: 39358329 
• DOI: https://doi.org/10.1038/s41467-024-52582-1
• Primary Citation Related Structures: 
  8Y9B, 8Y9C


• PubMed Abstract: 
  

  Clostridioides difficile toxin B (TcdB) is the key virulence factor accounting for C. difficile infection-associated symptoms. Effectively neutralizing different TcdB variants with a universal solution poses a significant challenge. Here we present the de novo design and characterization of pan-specific mini-protein binders against major TcdB subtypes. Our design successfully binds to the first receptor binding interface (RBI-1) of the varied TcdB subtypes, exhibiting affinities ranging from 20 pM to 10 nM. The cryo-electron microscopy (cryo-EM) structures of the mini protein binder in complex with TcdB1 and TcdB4 are consistent with the computational design models. The engineered and evolved variants of the mini-protein binder and chondroitin sulfate proteoglycan 4 (CSPG4), another natural receptor that binds to the second RBI (RBI-2) of TcdB, better neutralize major TcdB variants both in cells and in vivo, as demonstrated by the colon-loop assay using female mice. Our findings provide valuable starting points for the development of therapeutics targeting C. difficile infections (CDI).

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Organizational Affiliation: 
• Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang, 310024, China.
Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China.
Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.
Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China.
Center for Infectious Disease Research, School of Medicine, Westlake University, Hangzhou, Zhejiang, 310024, China.
Center for General Practice Medicine, Department of Infectious Diseases, Zhejiang Provincial People's Hospital, Hangzhou Medical College Affiliated People's Hospital, Hangzhou, Zhejiang, 310014, China.
Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang, 310024, China. [e-mail].
Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China. [e-mail].
Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China. [e-mail].
Center for Infectious Disease Research, School of Medicine, Westlake University, Hangzhou, Zhejiang, 310024, China. [e-mail].
Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang, 310024, China. [e-mail].
Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, 310024, China. [e-mail].
Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China. [e-mail].
Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, 310024, China. [e-mail].

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 278.27 kDa 
• Atom Count: 13,380 
• Modeled Residue Count: 1,672 
• Deposited Residue Count: 2,437 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Toxin B	A [auth B]	2,372	Clostridioides difficile	Mutation(s): 0  Gene Names: tcdB, toxB EC: 3.4.22
UniProt
Find proteins for P18177 (Clostridioides difficile) Explore P18177  Go to UniProtKB:  P18177

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
De novo design mini-binder	B [auth A]	65	synthetic construct	Mutation(s): 0

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ZN (Subject of Investigation/LOI)	C [auth B]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.20 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
MODEL REFINEMENT	PHENIX	1.19.2_4158:

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2024-08-28 
Deposition Author(s): Lv, X.C., Lu, P.L.

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Funding Organization	Location	Grant Number
Ministry of Science and Technology (MoST, China)	China	2020YFA0909200
National Natural Science Foundation of China (NSFC)	China	32301219

Revision History  

• Version 1.0: 2024-08-28
  Type: Initial release
  
• Version 1.1: 2024-10-09
  Changes: Data collection, Database references, Structure summary
• Version 1.2: 2024-10-16
  Changes: Data collection, Database references