1NQM

Structure of Savm-W120K, streptavidin mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.212 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Dimer-Tetramer Transition between Solution and Crystalline States of Streptavidin and Avidin Mutants.

Pazy, Y.Eisenberg-Domovich, Y.Laitinen, O.H.Kulomaa, M.S.Bayer, E.A.Wilchek, M.Livnah, O.

(2003) J.Bacteriol. 185: 4050-4056

  • Primary Citation of Related Structures:  1NQN

  • PubMed Abstract: 
  • The biotin-binding tetrameric proteins, streptavidin from Streptomyces avidinii and chicken egg white avidin, are excellent models for the study of subunit-subunit interactions of a multimeric protein. Efforts are thus being made to prepare mutated f ...

    The biotin-binding tetrameric proteins, streptavidin from Streptomyces avidinii and chicken egg white avidin, are excellent models for the study of subunit-subunit interactions of a multimeric protein. Efforts are thus being made to prepare mutated forms of streptavidin and avidin, which would form monomers or dimers, in order to examine their effect on quaternary structure and assembly. In the present communication, we compared the crystal structures of binding site W-->K mutations in streptavidin and avidin. In solution, both mutant proteins are known to form dimers, but upon crystallization, both formed tetramers with the same parameters as the native proteins. All of the intersubunit bonds were conserved, except for the hydrophobic interaction between biotin and the tryptophan that was replaced by lysine. In the crystal structure, the binding site of the mutated apo-avidin contains 3 molecules of structured water instead of the 5 contained in the native protein. The lysine side chain extends in a direction opposite that of the native tryptophan, the void being partially filled by an adjacent lysine residue. Nevertheless, the binding-site conformation observed for the mutant tetramer is an artificial consequence of crystal packing that would not be maintained in the solution-phase dimer. It appears that the dimer-tetramer transition may be concentration dependent, and the interaction among subunits obeys the law of mass action.


    Organizational Affiliation

    Department of Biological Chemistry, The Institute of Life Sciences, The Wolfson Centre for Applied Structural Biology, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904, Israel.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Streptavidin
A, B, C, D
136Streptomyces avidiniiN/A
Find proteins for P22629 (Streptomyces avidinii)
Go to UniProtKB:  P22629
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
BTN
Query on BTN

Download SDF File 
Download CCD File 
A, B, C, D
BIOTIN
C10 H16 N2 O3 S
YBJHBAHKTGYVGT-ZKWXMUAHSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
BTNΔH: -66.9 - -123 kJ/mol (99) BINDINGDB
BTNKd: 1 nM (99) BINDINGDB
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.212 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 50.433α = 90.00
b = 100.407β = 112.12
c = 52.511γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement
AMoREphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-07-15
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance