1ELZ

E. COLI ALKALINE PHOSPHATASE MUTANT (S102G)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.173 
  • R-Value Work: 0.138 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Kinetic and X-ray structural studies of three mutant E. coli alkaline phosphatases: insights into the catalytic mechanism without the nucleophile Ser102.

Stec, B.Hehir, M.J.Brennan, C.Nolte, M.Kantrowitz, E.R.

(1998) J.Mol.Biol. 277: 647-662

  • DOI: 10.1006/jmbi.1998.1635
  • Primary Citation of Related Structures:  1ELX, 1ELY

  • PubMed Abstract: 
  • Escherichia coli alkaline phosphatase (EC 3.1.3.1) is a non-specific phosphomonoesterase that catalyzes the hydrolysis reaction via a phosphoseryl intermediate to produce inorganic phosphate and the corresponding alcohol. We investigated the nature o ...

    Escherichia coli alkaline phosphatase (EC 3.1.3.1) is a non-specific phosphomonoesterase that catalyzes the hydrolysis reaction via a phosphoseryl intermediate to produce inorganic phosphate and the corresponding alcohol. We investigated the nature of the primary nucleophile, fulfilled by the deprotonated Ser102, in the catalytic mechanism by mutating this residue to glycine, alanine and cysteine. The efficiencies of the S102G, S102A and S102C enzymes were 6 x 10(5)-fold, 10(5)-fold and 10(4)-fold lower than the wild-type enzyme, respectively, as measured by the kcat/Km ratio, still substantially higher than the non-catalyzed reaction. In order to investigate the structural details of the altered active site, the enzymes were crystallized and their structures determined. The enzymes crystallized in a new crystal form corresponding to the space group P6322. Each structure has phosphate at each active site and shows little departure from the wild-type model. For the S102G and S102A enzymes, the phosphate occupies the same position as in the wild-type enzyme, while in the S102C enzyme it is displaced by 2.5 A. This kinetic and structural study suggests an explanation for differences in catalytic efficiency of the mutant enzymes and provides a means to study the nature and strength of different nucleophiles in the same environment. The analysis of these results provides insight into the mechanisms of other classes of phosphatases that do not utilize a serine nucleophile.


    Related Citations: 
    • Reaction Mechanism of Alkaline Phosphatase Based on Crystal Structures. Two-Metal Ion Catalysis
      Kim, E.E.,Wyckoff, H.W.
      (1991) J.Mol.Biol. 218: 449


    Organizational Affiliation

    Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02167, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ALKALINE PHOSPHATASE
A, B
449Escherichia coli (strain K12)Gene Names: phoA
EC: 3.1.3.1
Find proteins for P00634 (Escherichia coli (strain K12))
Go to UniProtKB:  P00634
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download SDF File 
Download CCD File 
A, B
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
ZN
Query on ZN

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Download CCD File 
A, B
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

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Download CCD File 
A, B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.173 
  • R-Value Work: 0.138 
  • Space Group: P 63 2 2
Unit Cell:
Length (Å)Angle (°)
a = 164.570α = 90.00
b = 164.500β = 90.00
c = 138.590γ = 120.00
Software Package:
Software NamePurpose
X-PLORphasing
XDSdata scaling
X-PLORmodel building
XDSdata reduction
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1998-05-27
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2011-11-16
    Type: Atomic model