2VVR

Crystal structure of the H99N mutant of ribose-5-phosphate isomerase B from E. coli soaked with ribose 5-phosphate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.188 
  • R-Value Observed: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

D-Ribose-5-Phosphate Isomerase B from Escherichia Coli is Also a Functional D-Allose-6-Phosphate Isomerase, While the Mycobacterium Tuberculosis Enzyme is not.

Roos, A.K.Mariano, S.Kowalinski, E.Salmon, L.Mowbray, S.L.

(2008) J Mol Biol 382: 667

  • DOI: 10.1016/j.jmb.2008.06.090
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Interconversion of D-ribose-5-phosphate (R5P) and D-ribulose-5-phosphate is an important step in the pentose phosphate pathway. Two unrelated enzymes with R5P isomerase activity were first identified in Escherichia coli, RpiA and RpiB. In this organism, the essential 5-carbon sugars were thought to be processed by RpiA, while the primary role of RpiB was suggested to instead be interconversion of the rare 6-carbon sugars D-allose-6-phosphate (All6P) and D-allulose-6-phosphate ...

    Interconversion of D-ribose-5-phosphate (R5P) and D-ribulose-5-phosphate is an important step in the pentose phosphate pathway. Two unrelated enzymes with R5P isomerase activity were first identified in Escherichia coli, RpiA and RpiB. In this organism, the essential 5-carbon sugars were thought to be processed by RpiA, while the primary role of RpiB was suggested to instead be interconversion of the rare 6-carbon sugars D-allose-6-phosphate (All6P) and D-allulose-6-phosphate. In Mycobacterium tuberculosis, where only an RpiB is found, the 5-carbon sugars are believed to be the enzyme's primary substrates. Here, we present kinetic studies examining the All6P isomerase activity of the RpiBs from these two organisms and show that only the E. coli enzyme can catalyze the reaction efficiently. All6P instead acts as an inhibitor of the M. tuberculosis enzyme in its action on R5P. X-ray studies of the M. tuberculosis enzyme co-crystallized with All6P and 5-deoxy-5-phospho-D-ribonohydroxamate (an inhibitor designed to mimic the 6-carbon sugar) and comparison with the E. coli enzyme's structure allowed us to identify differences in the active sites that explain the kinetic results. Two other structures, that of a mutant E. coli RpiB in which histidine 99 was changed to asparagine and that of wild-type M. tuberculosis enzyme, both co-crystallized with the substrate ribose-5-phosphate, shed additional light on the reaction mechanism of RpiBs generally.


    Organizational Affiliation

    Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Box 596, SE-751 24 Uppsala, Sweden.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
RIBOSE-5-PHOSPHATE ISOMERASE BA, B, C, D, E, F149Escherichia coli K-12Mutation(s): 1 
Gene Names: rpiByjcAb4090JW4051
EC: 5.3.1.6
Find proteins for P37351 (Escherichia coli (strain K12))
Explore P37351 
Go to UniProtKB:  P37351
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.188 
  • R-Value Observed: 0.190 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 89.701α = 90
b = 51.862β = 115.55
c = 207.209γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-07-08
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance