3LRG

Structure of anti-huntingtin VL domain


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.197 
  • R-Value Work: 0.170 
  • R-Value Observed: 0.172 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

A Disulfide-Free Single-Domain V(L) Intrabody with Blocking Activity towards Huntingtin Reveals a Novel Mode of Epitope Recognition.

Schiefner, A.Chatwell, L.Korner, J.Neumaier, I.Colby, D.W.Volkmer, R.Wittrup, K.D.Skerra, A.

(2011) J Mol Biol 414: 337-355

  • DOI: 10.1016/j.jmb.2011.09.034
  • Primary Citation of Related Structures:  
    3LRG, 3LRH

  • PubMed Abstract: 
  • We present the crystal structure and biophysical characterization of a human V(L) [variable domain immunoglobulin (Ig) light chain] single-domain intrabody that binds to the huntingtin (Htt) protein and has been engineered for antigen recognition in ...

    We present the crystal structure and biophysical characterization of a human V(L) [variable domain immunoglobulin (Ig) light chain] single-domain intrabody that binds to the huntingtin (Htt) protein and has been engineered for antigen recognition in the absence of its intradomain disulfide bond, otherwise conserved in the Ig fold. Analytical ultracentrifugation demonstrated that the αHtt-V(L) 12.3 domain is a stable monomer under physiological conditions even at concentrations >20 μM. Using peptide SPOT arrays, we identified the minimal binding epitope to be EKLMKAFESLKSFQ, comprising the N-terminal residues 5-18 of Htt and including the first residue of the poly-Gln stretch. X-ray structural analysis of αHtt-V(L) both as apo protein and in the presence of the epitope peptide revealed several interesting insights: first, the role of mutations acquired during the combinatorial selection process of the αHtt-V(L) 12.3 domain-initially starting from a single-chain Fv fragment-that are responsible for its stability as an individually soluble Ig domain, also lacking the disulfide bridge, and second, a previously unknown mode of antigen recognition, revealing a novel paratope. The Htt epitope peptide adopts a purely α-helical structure in the complex with αHtt-V(L) and is bound at the base of the complementarity-determining regions (CDRs) at the concave β-sheet that normally gives rise to the interface between the V(L) domain and its paired V(H) (variable domain Ig heavy chain) domain, while only few interactions with CDR-L1 and CDR-L3 are formed. Notably, this noncanonical mode of antigen binding may occur more widely in the area of in vitro selected antibody fragments, including other Ig-like scaffolds, possibly even if a V(H) domain is present.


    Organizational Affiliation

    Munich Center for Integrated Protein Science and Lehrstuhl für Biologische Chemie, Technische Universität München, 85350 Freising-Weihenstephan, Germany.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
anti-huntingtin VL domainAB121Homo sapiensMutation(s): 0 
Gene Names: VL12.3
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TRS
Query on TRS

Download Ideal Coordinates CCD File 
A
2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
C4 H12 N O3
LENZDBCJOHFCAS-UHFFFAOYSA-O
 Ligand Interaction
IMD
Query on IMD

Download Ideal Coordinates CCD File 
A
IMIDAZOLE
C3 H5 N2
RAXXELZNTBOGNW-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.197 
  • R-Value Work: 0.170 
  • R-Value Observed: 0.172 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 107.68α = 90
b = 107.68β = 90
c = 50.62γ = 90
Software Package:
Software NamePurpose
MAR345data collection
PHASERphasing
REFMACrefinement
XDSdata reduction
XSCALEdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-02-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2011-11-30
    Changes: Database references
  • Version 1.3: 2012-01-11
    Changes: Database references