4KTD

Fab fragment of HIV vaccine-elicited CD4bs-directed antibody, GE136, from non-human primate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.215 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Vaccine-elicited primate antibodies use a distinct approach to the HIV-1 primary receptor binding site informing vaccine redesign.

Tran, K.Poulsen, C.Guenaga, J.de Val Alda, N.Wilson, R.Sundling, C.Li, Y.Stanfield, R.L.Wilson, I.A.Ward, A.B.Karlsson Hedestam, G.B.Wyatt, R.T.

(2014) Proc Natl Acad Sci U S A 111: E738-E747

  • DOI: 10.1073/pnas.1319512111
  • Primary Citation of Related Structures:  
    4KTD, 4KTE

  • PubMed Abstract: 
  • HIV-1 neutralization requires Ab accessibility to the functional envelope glycoprotein (Env) spike. We recently reported the isolation of previously unidentified vaccine-elicited, CD4 binding site (CD4bs)-directed mAbs from rhesus macaques immunized with soluble Env trimers, indicating that this region is immunogenic in the context of subunit vaccination ...

    HIV-1 neutralization requires Ab accessibility to the functional envelope glycoprotein (Env) spike. We recently reported the isolation of previously unidentified vaccine-elicited, CD4 binding site (CD4bs)-directed mAbs from rhesus macaques immunized with soluble Env trimers, indicating that this region is immunogenic in the context of subunit vaccination. To elucidate the interaction of the trimer-elicited mAbs with gp120 and their insufficient interaction with the HIV-1 primary isolate spike, we crystallized the Fab fragments of two mAbs, GE136 and GE148. Alanine scanning of their complementarity-determining regions, coupled with epitope scanning of their epitopes on gp120, revealed putative contact residues at the Ab/gp120 interface. Docking of the GE136 and GE148 Fabs to gp120, coupled with EM reconstructions of these nonbroadly neutralizing mAbs (non-bNAbs) binding to gp120 monomers and EM modeling to well-ordered trimers, suggested Ab approach to the CD4bs by a vertical angle of access relative to the more lateral mode of interaction used by the CD4bs-directed bNAbs VRC01 and PGV04. Fitting the structures into the available cryo-EM native spike density indicated clashes between these two vaccine-elicited mAbs and the topside variable region spike cap, whereas the bNAbs duck under this quaternary shield to access the CD4bs effectively on primary HIV isolates. These results provide a structural basis for the limited neutralizing breadth observed by current vaccine-induced, CD4bs-directed Abs and highlight the need for better ordered trimer immunogens. The analysis presented here therefore provides valuable information to guide HIV-1 vaccine immunogen redesign.


    Organizational Affiliation

    International AIDS Vaccine Initiative Neutralizing Antibody Center, Departments of Integrative Structural and Computational Biology and Immunology and Microbial Science, and Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA 92037.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
GE136 Heavy Chain FabA [auth H]234Macaca mulattaMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
GE136 Light Chain FabB [auth L]219Macaca mulattaMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.215 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 44.92α = 90
b = 71.5β = 90
c = 154.24γ = 90
Software Package:
Software NamePurpose
XSCALEdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
JBluIce-EPICSdata collection
XDSdata reduction
Auto-Rickshawphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-02-05
    Type: Initial release
  • Version 1.1: 2014-03-19
    Changes: Database references
  • Version 1.2: 2017-11-15
    Changes: Refinement description