2IFD

Crystal structure of a remote binding site mutant, R492L, of CDC25B Phosphatase catalytic domain


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.191 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Kinetic and structural studies of specific protein-protein interactions in substrate catalysis by Cdc25B phosphatase.

Sohn, J.Buhrman, G.Rudolph, J.

(2007) Biochemistry 46: 807-818

  • DOI: 10.1021/bi061257y
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Using a combination of steady-state and single-turnover kinetics, we probe substrate association, dissociation, and chemistry for the reaction of Cdc25B phosphatase with its Cdk2-pTpY/CycA protein substrate. The rate constant for substrate associatio ...

    Using a combination of steady-state and single-turnover kinetics, we probe substrate association, dissociation, and chemistry for the reaction of Cdc25B phosphatase with its Cdk2-pTpY/CycA protein substrate. The rate constant for substrate association for the wild-type enzyme is 1.3 x 10(6) M(-1) s(-1). The rate constant for dissociation is slow compared to the rate constant for phosphate transfer to form the phospho-enzyme intermediate (k2 = 1.1 s(-1)), making Cdk2-pTpY/CycA a sticky substrate. Compared to the wild type, all hotspot mutants of residues at the remote docking site that specifically affect catalysis with the protein substrate (Arg488, Arg492, and Tyr497 on Cdc25B and Asp206 on Cdk2) have greatly slowed rate constants of association (70- to 4500-fold), and some mutants have decreased k2 values compared to that of the wild type. Most dramatically, R492L, despite showing no significant changes in a crystal structure at 2.0 A resolution, has an approximately 100-fold decrease in k2 compared to that of wild-type Cdc25B. The active site C473S mutant binds tightly to and dissociates slowly from Cdk2-pTpY/CycA (Kd = 10 nM, k(off) = 0.01 s(-1)). In contrast, the C473D mutant, despite showing only localized perturbations in the active site at 1.6 A resolution, has a much weaker affinity and dissociates rapidly (Kd of 2 microM, k(off) > 2 s(-1)) from the protein substrate. Overall, we demonstrate that the association of Cdc25B with its Cdk2-pTpY/CycA substrate is governed to a significant extent by the interactions of the remote hotspot residues, whereas dissociation is governed by interactions at the active site.


    Organizational Affiliation

    Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
M-phase inducer phosphatase 2
A
175Homo sapiensMutation(s): 1 
Gene Names: CDC25B (CDC25HU2)
EC: 3.1.3.48
Find proteins for P30305 (Homo sapiens)
Go to Gene View: CDC25B
Go to UniProtKB:  P30305
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
CL
Query on CL

Download SDF File 
Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.191 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 49.957α = 90.00
b = 71.320β = 90.00
c = 75.060γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
HKL-2000data reduction
HKL-2000data scaling
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-02-27
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance