1B2X

BARNASE WILDTYPE STRUCTURE AT PH 7.5 FROM A CRYO_COOLED CRYSTAL AT 100K


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.173 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

A structural double-mutant cycle: estimating the strength of a buried salt bridge in barnase.

Vaughan, C.K.Harryson, P.Buckle, A.M.Fersht, A.R.

(2002) Acta Crystallogr.,Sect.D 58: 591-600

  • Primary Citation of Related Structures:  1B20, 1B21, 1B2Z

  • PubMed Abstract: 
  • Double-mutant cycles are widely used in the field of protein engineering to measure intermolecular and intramolecular interactions. Ideally, there should be no structural rearrangement of the protein on making the two single mutations and the double ...

    Double-mutant cycles are widely used in the field of protein engineering to measure intermolecular and intramolecular interactions. Ideally, there should be no structural rearrangement of the protein on making the two single mutations and the double mutation within the cycle. However, structural pertubation on mutation does not preclude the use of this method, providing the sum of the changes in the single mutants equals the change in the double mutant. In this way, the energy associated with any structural rearrangement cancels in the double-mutant cycle. Previously, the contribution of a buried salt bridge between Arg69 and Asp93 in barnase to the stability of the folded protein has been determined by double-mutant cycle analysis. In order to determine whether the measured interaction of -14.0 kJ mol(-1) represents the true interaction energy, the crystal structure of each mutant within the double-mutant cycle was solved. Although mutation results in structural shifts, the majority of those in the single mutants are also found in the double mutant; their energetic effects in the double-mutant cycle are therefore cancelled. This study highlights the robust nature of the double-mutant cycle analysis.


    Related Citations: 
    • Molecular Structure of a New Family of Ribonucleases
      Mauguen, Y.,Hartley, R.W.,Dodson, E.J.,Dodson, G.G.,Bricogne, G.,Chothia, C.,Jack, A.
      (1982) Nature 29: 162


    Organizational Affiliation

    Section of Structural Biology, The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, England.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (BARNASE)
A, B, C
110Bacillus amyloliquefaciensEC: 3.1.27.-
Find proteins for P00648 (Bacillus amyloliquefaciens)
Go to UniProtKB:  P00648
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
C
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.173 
  • Space Group: P 32
Unit Cell:
Length (Å)Angle (°)
a = 57.630α = 90.00
b = 57.630β = 90.00
c = 80.980γ = 120.00
Software Package:
Software NamePurpose
iMOSFLMdata reduction
CCP4data scaling
X-PLORmodel building
SCALAdata scaling
X-PLORphasing
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1998-12-09
    Type: Initial release
  • Version 1.1: 2008-04-26
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-04
    Type: Advisory, Refinement description