1P50

Transition state structure of an Arginine Kinase mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.172 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The putative catalytic bases have, at most, an accessory role in the mechanism of arginine kinase.

Pruett, P.S.Azzi, A.Clark, S.A.Yousef, M.S.Gattis, J.L.Somasundaram, T.Ellington, W.R.Chapman, M.S.

(2003) J.Biol.Chem. 278: 26952-26957

  • DOI: 10.1074/jbc.M212931200
  • Primary Citation of Related Structures:  1P52

  • PubMed Abstract: 
  • Arginine kinase is a member of the phosphagen kinase family that includes creatine kinase and likely shares a common reaction mechanism in catalyzing the buffering of cellular ATP energy levels. Abstraction of a proton from the substrate guanidinium ...

    Arginine kinase is a member of the phosphagen kinase family that includes creatine kinase and likely shares a common reaction mechanism in catalyzing the buffering of cellular ATP energy levels. Abstraction of a proton from the substrate guanidinium by a catalytic base has long been thought to be an early mechanistic step. The structure of arginine kinase as a transition state analog complex (Zhou, G., Somasundaram, T., Blanc, E., Parthasarathy, G., Ellington, W. R., and Chapman, M. S. (1998) Proc. Natl. Acad. Sci. U. S. A. 95, 8449-8454) showed that Glu-225 and Glu-314 were the only potential catalytic residues contacting the phosphorylated nitrogen. In the present study, these residues were changed to Asp, Gln, and Val or Ala in several single and multisite mutant enzymes. These mutations had little impact on the substrate binding constants. The effect upon activity varied with reductions in kcat between 3000-fold and less than 2-fold. The retention of significant activity in some mutants contrasts with published studies of homologues and suggests that acid-base catalysis by these residues may enhance the rate but is not absolutely essential. Crystal structures of mutant enzymes E314D at 1.9 A and E225Q at 2.8 A resolution showed that the precise alignment of substrates is subtly distorted. Thus, pre-ordering of substrates might be just as important as acid-base chemistry, electrostatics, or other potential effects in the modest impact of these residues upon catalysis.


    Organizational Affiliation

    Departments of Chemistry and Biochemistry and Biological Science and the Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306-4380, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Arginine kinase
A
356Limulus polyphemusEC: 2.7.3.3
Find proteins for P51541 (Limulus polyphemus)
Go to UniProtKB:  P51541
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ADP
Query on ADP

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Download CCD File 
A
ADENOSINE-5'-DIPHOSPHATE
C10 H15 N5 O10 P2
XTWYTFMLZFPYCI-KQYNXXCUSA-N
 Ligand Interaction
MG
Query on MG

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Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
ARG
Query on ARG

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Download CCD File 
A
ARGININE
C6 H15 N4 O2
ODKSFYDXXFIFQN-BYPYZUCNSA-O
 Ligand Interaction
NO3
Query on NO3

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Download CCD File 
A
NITRATE ION
N O3
NHNBFGGVMKEFGY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.172 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 65.454α = 90.00
b = 71.246β = 90.00
c = 80.116γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement
CNSphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-06-17
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance