2MNR

MECHANISM OF THE REACTION CATALYZED BY MANDELATE RACEMASE. 2. CRYSTAL STRUCTURE OF MANDELATE RACEMASE AT 2.5 ANGSTROMS RESOLUTION: IDENTIFICATION OF THE ACTIVE SITE AND POSSIBLE CATALYTIC RESIDUES


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Work: 0.162 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Mechanism of the reaction catalyzed by mandelate racemase. 2. Crystal structure of mandelate racemase at 2.5-A resolution: identification of the active site and possible catalytic residues.

Neidhart, D.J.Howell, P.L.Petsko, G.A.Powers, V.M.Li, R.S.Kenyon, G.L.Gerlt, J.A.

(1991) Biochemistry 30: 9264-9273


  • PubMed Abstract: 
  • The crystal structure of mandelate racemase (MR) has been solved at 3.0-A resolution by multiple isomorphous replacement and subsequently refined against X-ray diffraction data to 2.5-A resolution by use of both molecular dynamics refinement (XPLOR) ...

    The crystal structure of mandelate racemase (MR) has been solved at 3.0-A resolution by multiple isomorphous replacement and subsequently refined against X-ray diffraction data to 2.5-A resolution by use of both molecular dynamics refinement (XPLOR) and restrained least-squares refinement (PROLSQ). The current crystallographic R-factor for this structure is 18.3%. MR is composed of two major structural domains and a third, smaller, C-terminal domain. The N-terminal domain has an alpha + beta topology consisting of a three-stranded antiparallel beta-sheet followed by an antiparallel four alpha-helix bundle. The central domain is a singly wound parallel alpha/beta-barrel composed of eight central strands of beta-sheet and seven alpha-helices. The C-terminal domain consists of an irregular L-shaped loop with several short sections of antiparallel beta-sheet and two short alpha-helices. This C-terminal domain partially covers the junction between the major domains and occupies a region of the central domain that is filled by an eight alpha-helix in all other known parallel alpha/beta-barrels except for the barrel domain in muconate lactonizing enzyme (MLE) [Goldman, A., Ollis, D. L., & Steitz, T. A. (1987) J. Mol. Biol. 194, 143] whose overall polypeptide fold and amino acid sequence are strikingly similar to those of MR [Neidhart, D. J., Kenyon, G. L., Gerlt, J. A., & Petsko, G. A. (1990) Nature 347, 692]. In addition, the crystal structure reveals that, like MLE, MR is tightly packed as an octamer of identical subunits. The active site of MR is located between the two major domains, at the C-terminal ends of the beta-strands in the alpha/beta-barrel domain. The catalytically essential divalent metal ion is ligated by three side-chain carboxyl groups contributed by residues of the central beta-sheet. A model of a productive substrate complex of MR has been constructed on the basis of difference Fourier analysis at 3.5-A resolution of a complex between MR and (R,S)-p-iodomandelate, permitting identification of residues that may participate in substrate binding and catalysis. The ionizable groups of both Lys 166 and His 297 are positioned to interact with the chiral center of substrate, suggesting that both of these residues may function as acid/base catalysts.(ABSTRACT TRUNCATED AT 400 WORDS)


    Related Citations: 
    • Mandelate Racemase and Muconate Lactonizing Enzyme are Mechanistically Distinct and Structurally Homologous
      Neidhart, D.J.,Kenyon, G.L.,Gerlt, J.A.,Petsko, G.A.
      (1990) Nature 347: 692


    Organizational Affiliation

    Department of Chemistry, Massachusetts Institute of Technology, Cambridge 02139.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
MANDELATE RACEMASE
A
357Pseudomonas putidaMutation(s): 0 
Gene Names: mdlA
EC: 5.1.2.2
Find proteins for P11444 (Pseudomonas putida)
Go to UniProtKB:  P11444
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MN
Query on MN

Download SDF File 
Download CCD File 
A
MANGANESE (II) ION
Mn
WAEMQWOKJMHJLA-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Work: 0.162 
  • Space Group: I 4 2 2
Unit Cell:
Length (Å)Angle (°)
a = 125.000α = 90.00
b = 125.000β = 90.00
c = 106.200γ = 90.00
Software Package:
Software NamePurpose
PROLSQrefinement
X-PLORrefinement
X-PLORphasing
X-PLORmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1994-01-31
    Type: Initial release
  • Version 1.1: 2008-03-03
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance
  • Version 1.3: 2011-11-16
    Type: Atomic model
  • Version 1.4: 2017-11-29
    Type: Derived calculations, Other