4XVX

Crystal structure of an acyl-ACP dehydrogenase

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.175 
  • R-Value Observed: 0.176 

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This is version 1.3 of the entry. See complete history. 


Literature

A covalent adduct of MbtN, an acyl-ACP dehydrogenase from Mycobacterium tuberculosis, reveals an unusual acyl-binding pocket.

Chai, A.F., Bulloch, E.M., Evans, G.L., Lott, J.S., Baker, E.N., Johnston, J.M.

(2015) Acta Crystallogr D Biol Crystallogr 71: 862-872

  • DOI: 10.1107/S1399004715001650
  • Primary Citation of Related Structures:  
    4XVX

  • PubMed Abstract: 

    • Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis. Access to iron in host macrophages depends on iron-chelating siderophores called mycobactins and is strongly correlated with Mtb virulence. Here, the crystal structure of an Mtb ...

    Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis. Access to iron in host macrophages depends on iron-chelating siderophores called mycobactins and is strongly correlated with Mtb virulence. Here, the crystal structure of an Mtb enzyme involved in mycobactin biosynthesis, MbtN, in complex with its FAD cofactor is presented at 2.30 Å resolution. The polypeptide fold of MbtN conforms to that of the acyl-CoA dehydrogenase (ACAD) family, consistent with its predicted role of introducing a double bond into the acyl chain of mycobactin. Structural comparisons and the presence of an acyl carrier protein, MbtL, in the same gene locus suggest that MbtN acts on an acyl-(acyl carrier protein) rather than an acyl-CoA. A notable feature of the crystal structure is the tubular density projecting from N(5) of FAD. This was interpreted as a covalently bound polyethylene glycol (PEG) fragment and resides in a hydrophobic pocket where the substrate acyl group is likely to bind. The pocket could accommodate an acyl chain of 14-21 C atoms, consistent with the expected length of the mycobactin acyl chain. Supporting this, steady-state kinetics show that MbtN has ACAD activity, preferring acyl chains of at least 16 C atoms. The acyl-binding pocket adopts a different orientation (relative to the FAD) to other structurally characterized ACADs. This difference may be correlated with the apparent ability of MbtN to catalyse the formation of an unusual cis double bond in the mycobactin acyl chain.

    Organizational Affiliation: 

    Laboratory of Structural Biology, School of Biological Sciences and Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Acyl-[acyl-carrier-protein] dehydrogenase MbtNA, B389Mycobacterium tuberculosis H37RvMutation(s): 0 
Gene Names: mbtN, fadE14, Rv1346, MTCY02B10.10
EC: 1.3.99
Find proteins for P9WQF9 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore P9WQF9 
Go to UniProtKB:  P9WQF9
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FDA
Query on FDA
Download CCD File 
A, B
DIHYDROFLAVINE-ADENINE DINUCLEOTIDE
C27 H35 N9 O15 P2
YPZRHBJKEMOYQH-UYBVJOGSSA-N		 Ligand Interaction
P33
Query on P33
Download CCD File 
A
3,6,9,12,15,18-HEXAOXAICOSANE-1,20-DIOL
C14 H30 O8
XPJRQAIZZQMSCM-UHFFFAOYSA-N		 Ligand Interaction
P6G
Query on P6G
Download CCD File 
B
HEXAETHYLENE GLYCOL
C12 H26 O7
IIRDTKBZINWQAW-UHFFFAOYSA-N		 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.175 
  • R-Value Observed: 0.176 
  • Space Group: H 3 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 139.104α = 90
b = 139.104β = 90
c = 253.093γ = 120
Software Package:
Software NamePurpose
XDSdata reduction
SCALAdata scaling
MOLREPphasing
BUSTERrefinement
PHASERphasing

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-02-11
    Type: Initial release
  • Version 1.1: 2015-04-08
    Changes: Database references
  • Version 1.2: 2015-06-03
    Changes: Database references
  • Version 1.3: 2017-09-27
    Changes: Author supporting evidence, Data collection, Derived calculations, Refinement description, Source and taxonomy