4K3G

Immunoglobulin lambda variable domain L5(L89S) fluorogen activating protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.193 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Malachite Green Mediates Homodimerization of Antibody VL Domains to Form a Fluorescent Ternary Complex with Singular Symmetric Interfaces.

Szent-Gyorgyi, C.Stanfield, R.L.Andreko, S.Dempsey, A.Ahmed, M.Capek, S.Waggoner, A.S.Wilson, I.A.Bruchez, M.P.

(2013) J.Mol.Biol. 425: 4595-4613

  • DOI: 10.1016/j.jmb.2013.08.014
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • We report that a symmetric small-molecule ligand mediates the assembly of antibody light chain variable domains (VLs) into a correspondent symmetric ternary complex with novel interfaces. The L5* fluorogen activating protein is a VL domain that binds ...

    We report that a symmetric small-molecule ligand mediates the assembly of antibody light chain variable domains (VLs) into a correspondent symmetric ternary complex with novel interfaces. The L5* fluorogen activating protein is a VL domain that binds malachite green (MG) dye to activate intense fluorescence. Crystallography of liganded L5* reveals a 2:1 protein:ligand complex with inclusive C2 symmetry, where MG is almost entirely encapsulated between an antiparallel arrangement of the two VL domains. Unliganded L5* VL domains crystallize as a similar antiparallel VL/VL homodimer. The complementarity-determining regions are spatially oriented to form novel VL/VL and VL/ligand interfaces that tightly constrain a propeller conformer of MG. Binding equilibrium analysis suggests highly cooperative assembly to form a very stable VL/MG/VL complex, such that MG behaves as a strong chemical inducer of dimerization. Fusion of two VL domains into a single protein tightens MG binding over 1000-fold to low picomolar affinity without altering the large binding enthalpy, suggesting that bonding interactions with ligand and restriction of domain movements make independent contributions to binding. Fluorescence activation of a symmetrical fluorogen provides a selection mechanism for the isolation and directed evolution of ternary complexes where unnatural symmetric binding interfaces are favored over canonical antibody interfaces. As exemplified by L5*, these self-reporting complexes may be useful as modulators of protein association or as high-affinity protein tags and capture reagents.


    Organizational Affiliation

    Molecular Biosensor and Imaging Center, Carnegie Mellon University, Pittsburgh, PA 15213, USA. Electronic address: css@andrew.cmu.edu.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
immunoglobulin lambda variable domain L5(L89S)
A, B
118N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MAN
Query on MAN

Download SDF File 
Download CCD File 
B
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.193 
  • Space Group: P 41
Unit Cell:
Length (Å)Angle (°)
a = 54.860α = 90.00
b = 54.860β = 90.00
c = 95.320γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
Blu-Icedata collection
HKL-2000data reduction
PHASERphasing
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-10-09
    Type: Initial release
  • Version 1.1: 2013-11-13
    Type: Database references