2G5F

The structure of MbtI from Mycobacterium Tuberculosis, the first enzyme in the synthesis of Mycobactin, reveals it to be a salicylate synthase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.208 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

The Structure of MbtI from Mycobacterium tuberculosis, the First Enzyme in the Biosynthesis of the Siderophore Mycobactin, Reveals It To Be a Salicylate Synthase

Harrison, A.J.Gardenborg, T.Yu, M.Middleditch, M.Ramsay, R.J.Baker, E.N.Lott, J.S.

(2006) J Bacteriol 188: 6081-6091

  • DOI: 10.1128/JB.00338-06
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • The ability to acquire iron from the extracellular environment is a key determinant of pathogenicity in mycobacteria. Mycobacterium tuberculosis acquires iron exclusively via the siderophore mycobactin T, the biosynthesis of which depends on the prod ...

    The ability to acquire iron from the extracellular environment is a key determinant of pathogenicity in mycobacteria. Mycobacterium tuberculosis acquires iron exclusively via the siderophore mycobactin T, the biosynthesis of which depends on the production of salicylate from chorismate. Salicylate production in other bacteria is either a two-step process involving an isochorismate synthase (chorismate isomerase) and a pyruvate lyase, as observed for Pseudomonas aeruginosa, or a single-step conversion catalyzed by a salicylate synthase, as with Yersinia enterocolitica. Here we present the structure of the enzyme MbtI (Rv2386c) from M. tuberculosis, solved by multiwavelength anomalous diffraction at a resolution of 1.8 A, and biochemical evidence that it is the salicylate synthase necessary for mycobactin biosynthesis. The enzyme is critically dependent on Mg2+ for activity and produces salicylate via an isochorismate intermediate. MbtI is structurally similar to salicylate synthase (Irp9) from Y. enterocolitica and the large subunit of anthranilate synthase (TrpE) and shares the overall architecture of other chorismate-utilizing enzymes, such as the related aminodeoxychorismate synthase PabB. Like Irp9, but unlike TrpE or PabB, MbtI is neither regulated by nor structurally stabilized by bound tryptophan. The structure of MbtI is the starting point for the design of inhibitors of siderophore biosynthesis, which may make useful lead compounds for the production of new antituberculosis drugs, given the strong dependence of pathogenesis on iron acquisition in M. tuberculosis.


    Organizational Affiliation

    Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
COG0147: Anthranilate/para-aminobenzoate synthases component IA, B, C, D450Mycobacterium tuberculosis H37RvMutation(s): 0 
Gene Names: mbtItrpE2Rv2386c
EC: 5.4.99.5 (UniProt), 4.2.99.21 (UniProt), 5.4.4.2 (UniProt)
Find proteins for P9WFX1 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore P9WFX1 
Go to UniProtKB:  P9WFX1
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download CCD File 
A, B, C, D
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
PYR
Query on PYR

Download CCD File 
A, B
PYRUVIC ACID
C3 H4 O3
LCTONWCANYUPML-UHFFFAOYSA-N
 Ligand Interaction
IMD
Query on IMD

Download CCD File 
A, C, D
IMIDAZOLE
C3 H5 N2
RAXXELZNTBOGNW-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.208 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.82α = 90
b = 163.37β = 90
c = 194.93γ = 90
Software Package:
Software NamePurpose
CNSrefinement
PDB_EXTRACTdata extraction
MOSFLMdata reduction
CCP4data scaling
SHARPphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-09-05
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Source and taxonomy, Version format compliance