4D8F

Chlamydia trachomatis NrdB with a Mn/Fe cofactor (procedure 1 - high Mn)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.186 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Evidence that the beta subunit of Chlamydia trachomatis ribonucleotide reductase is active with the manganese ion of its manganese(IV)/iron(III) cofactor in site 1.

Dassama, L.M.Boal, A.K.Krebs, C.Rosenzweig, A.C.Bollinger, J.M.

(2012) J.Am.Chem.Soc. 134: 2520-2523

  • DOI: 10.1021/ja211314p
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The reaction of a class I ribonucleotide reductase (RNR) begins when a cofactor in the β subunit oxidizes a cysteine residue ~35 Å away in the α subunit, generating a thiyl radical. In the class Ic enzyme from Chlamydia trachomatis (Ct), the cysteine ...

    The reaction of a class I ribonucleotide reductase (RNR) begins when a cofactor in the β subunit oxidizes a cysteine residue ~35 Å away in the α subunit, generating a thiyl radical. In the class Ic enzyme from Chlamydia trachomatis (Ct), the cysteine oxidant is the Mn(IV) ion of a Mn(IV)/Fe(III) cluster, which assembles in a reaction between O(2) and the Mn(II)/Fe(II) complex of β. The heterodinuclear nature of the cofactor raises the question of which site, 1 or 2, contains the Mn(IV) ion. Because site 1 is closer to the conserved location of the cysteine-oxidizing tyrosyl radical of class Ia and Ib RNRs, we suggested that the Mn(IV) ion most likely resides in this site (i.e., (1)Mn(IV)/(2)Fe(III)), but a subsequent computational study favored its occupation of site 2 ((1)Fe(III)/(2)Mn(IV)). In this work, we have sought to resolve the location of the Mn(IV) ion in Ct RNR-β by correlating X-ray crystallographic anomalous scattering intensities with catalytic activity for samples of the protein reconstituted in vitro by two different procedures. In samples containing primarily Mn(IV)/Fe(III) clusters, Mn preferentially occupies site 1, but some anomalous scattering from site 2 is observed, implying that both (1)Mn(II)/(2)Fe(II) and (1)Fe(II)/(2)Mn(II) complexes are competent to react with O(2) to produce the corresponding oxidized states. However, with diminished Mn(II) loading in the reconstitution, there is no evidence for Mn occupancy of site 2, and the greater activity of these "low-Mn" samples on a per-Mn basis implies that the (1)Mn(IV)/(2)Fe(III)-β is at least the more active of the two oxidized forms and may be the only active form.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Ribonucleoside-diphosphate reductase subunit beta
A, B, C, D
366Chlamydia trachomatis (strain D/UW-3/Cx)Mutation(s): 0 
Gene Names: nrdB
EC: 1.17.4.1
Find proteins for O84835 (Chlamydia trachomatis (strain D/UW-3/Cx))
Go to UniProtKB:  O84835
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MN
Query on MN

Download SDF File 
Download CCD File 
A, B, C, D
MANGANESE (II) ION
Mn
WAEMQWOKJMHJLA-UHFFFAOYSA-N
 Ligand Interaction
FE
Query on FE

Download SDF File 
Download CCD File 
A, B, C, D
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
ACY
Query on ACY

Download SDF File 
Download CCD File 
A, B
ACETIC ACID
C2 H4 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.186 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 75.221α = 90.00
b = 97.998β = 97.79
c = 100.291γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
SCALEPACKdata scaling
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-02-15
    Type: Initial release
  • Version 1.1: 2013-06-19
    Type: Database references
  • Version 1.2: 2017-11-15
    Type: Refinement description