7RIC

Griffithsin variant Y28W/Y68W/Y110W


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.189 
  • R-Value Work: 0.158 
  • R-Value Observed: 0.161 

Starting Model: experimental
View more details

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

C 3 -Symmetric Aromatic Core of Griffithsin Is Essential for Potent Anti-HIV Activity.

Sun, J.Zhao, G.Bylund, T.Lee, M.Adibhatla, S.Kwong, P.D.Chuang, G.Y.Rawi, R.Bewley, C.A.

(2022) ACS Chem Biol 17: 1450-1459

  • DOI: https://doi.org/10.1021/acschembio.1c00990
  • Primary Citation of Related Structures:  
    7RIA, 7RIB, 7RIC, 7RID, 7RKG, 7RKI

  • PubMed Abstract: 

    Lectins, carbohydrate-binding proteins of nonimmune origin, bind to carbohydrates and glycan shields present on the surfaces of cells and viral spike proteins. Lectins thus hold great promise as therapeutic and diagnostic proteins, exemplified by their potent antiviral activities and the desire to engineer synthetic carbohydrate receptors based on lectin recognition principles. Here, we describe a new carbohydrate-binding architectural motif─namely, a C 3 -symmetric tyrosine-based aromatic core, present in the therapeutic lectin griffithsin (GRFT). By using structure-based amino acid substitutions, X-ray crystallography, molecular dynamics (MD) simulations, and HIV-1 neutralization assays, we show that this core is critical for potent (pM) antiviral activity and nanomolar binding to the glycan shield largely consisting of high mannose glycans. Crystal structures and MD simulations show that CH-π interactions stabilize the aromatic cluster to maintain the three pseudo-symmetric carbohydrate-binding sites, nonaromatic amino acid substitutions (Tyr to Ala) abrogate antiviral activity, and increasing the aromatic CH-π edge-to-centroid interface via a Tyr to Trp substitution yields a GRFT variant with improved potency and increased residence time of Man-9 observed in MD simulations. NMR titrations of a Tyr-to-Ala variant indicate that disruption of the aromatic prevents the intermolecular crosslinking between two equivalents of Man-9 and one carbohydrate-binding face observed in wild-type GRFT and known to be critical for picomolar potency of this lectin. This C 3 -symmetric aromatic core defines a new recognition motif for the design of carbohydrate receptors and suggests principles for engineering known lectins to have increased affinity and stability.


  • Organizational Affiliation

    Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Griffithsin142Griffithsia sp. Q66D336Mutation(s): 4 
UniProt
Find proteins for P84801 (Griffithsia sp. (strain Q66D336))
Explore P84801 
Go to UniProtKB:  P84801
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP84801
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.189 
  • R-Value Work: 0.158 
  • R-Value Observed: 0.161 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 71.162α = 90
b = 71.162β = 90
c = 71.488γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
PHENIXphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2022-05-18
    Type: Initial release
  • Version 1.1: 2022-11-30
    Changes: Database references
  • Version 1.2: 2023-10-25
    Changes: Data collection, Refinement description