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: 1.90 Å
  • R-Value Work: 0.162 
  • R-Value Observed: 0.162 

wwPDB Validation   3D Report Full Report


This is version 1.7 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

  • DOI: https://doi.org/10.1021/bi00102a019
  • Primary Citation of Related Structures:  
    2MNR

  • 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) 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)


  • Organizational Affiliation

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


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
MANDELATE RACEMASE357Pseudomonas putidaMutation(s): 0 
EC: 5.1.2.2
UniProt
Find proteins for P11444 (Pseudomonas putida)
Explore P11444 
Go to UniProtKB:  P11444
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP11444
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Work: 0.162 
  • R-Value Observed: 0.162 
  • Space Group: I 4 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 125α = 90
b = 125β = 90
c = 106.2γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
PROLSQrefinement
X-PLORrefinement
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1994-01-31
    Type: Initial release
  • Version 1.1: 2008-03-03
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2011-11-16
    Changes: Atomic model
  • Version 1.4: 2017-11-29
    Changes: Derived calculations, Other
  • Version 1.5: 2019-07-17
    Changes: Data collection, Refinement description
  • Version 1.6: 2019-08-14
    Changes: Data collection, Refinement description
  • Version 1.7: 2024-02-21
    Changes: Data collection, Database references, Derived calculations