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CRYSTAL STRUCTURES OF THE BINARY CA2+ AND PDTP COMPLEXES AND THE TERNARY COMPLEX OF THE ASP 21->GLU MUTANT OF STAPHYLOCOCCAL NUCLEASE. IMPLICATIONS FOR CATALYSIS AND LIGAND BINDING


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Work: 0.174 

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This is version 1.3 of the entry. See complete history

Literature

Crystal structures of the binary Ca2+ and pdTp complexes and the ternary complex of the Asp21-->Glu mutant of staphylococcal nuclease. Implications for catalysis and ligand binding.

Libson, A.M.Gittis, A.G.Lattman, E.E.

(1994) Biochemistry 33: 8007-8016

  • Primary Citation of Related Structures:  1ENA, 2ENB

  • PubMed Abstract: 
  • The crystal structure of the Asp21-->Glu mutant (D21E) of staphylococcal nuclease (SNase) has been determined in three different complex forms. The structure of the D21E ternary complex in which D21E is bound to both Ca2+ and the transition-state ana ...

    The crystal structure of the Asp21-->Glu mutant (D21E) of staphylococcal nuclease (SNase) has been determined in three different complex forms. The structure of the D21E ternary complex in which D21E is bound to both Ca2+ and the transition-state analogue, thymidine 3',5'-diphosphate (pdTp), was determined to 1.95-A resolution. The structures of both binary complexes, D21E bound either to Ca2+ or pdTp, were determined to 2.15- and 2.05-A resolution, respectively. In the ternary structure, we find a 1.5-A movement of the Ca2+ in the active site, evidence of bidentate coordination of Ca2+ by Glu21 and inner-sphere coordination of the Ca2+ by Glu43. Comparison of the D21E binary structures with the ternary model shows large movements of active site side chains expected to play a direct role in catalysis. Glu43 moves in the binary nucleotide complex, whereas Arg35 is oriented differently in the binary metal complex. From these changes, we seek to explain the basis for the 1500-fold decrease in Vmax of D21E relative to wild-type SNase (WT). Furthermore, we describe direct structural evidence which explains the cooperativity of Ca2+ and pdTp binding in the ternary complex relative to that of the binary complexes.


    Organizational Affiliation

    Department of Biophysics & Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland 21205.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
STAPHYLOCOCCAL NUCLEASE
A
149Staphylococcus aureusGene Names: nuc
EC: 3.1.31.1
Find proteins for P00644 (Staphylococcus aureus)
Go to UniProtKB:  P00644
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
THP
Query on THP

Download SDF File 
Download CCD File 
A
THYMIDINE-3',5'-DIPHOSPHATE
C10 H16 N2 O11 P2
CSNCBOPUCJOHLS-XLPZGREQSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Work: 0.174 
  • Space Group: P 41
Unit Cell:
Length (Å)Angle (°)
a = 48.050α = 90.00
b = 48.050β = 90.00
c = 63.000γ = 90.00
Software Package:
Software NamePurpose
X-PLORphasing
X-PLORrefinement
PROLSQrefinement
X-PLORmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1994-05-31
    Type: Initial release
  • Version 1.1: 2008-03-03
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-11-29
    Type: Derived calculations, Other