Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 36.92 kDa 
• Atom Count: 2416 
• Residue Count: 281 
• Unique protein chains: 1

2FK8

Crystal structure of Hma (MmaA4) from Mycobacterium tuberculosis complexed with S-adenosylmethionine

• DOI: 10.2210/pdb2FK8/pdb

• Classification: TRANSFERASE
• Organism(s): Mycobacterium tuberculosis H37Rv
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2006-01-04 Released: 2006-01-17 
• Deposition Author(s): Boissier, F., Guillet, V., Mourey, L.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.239 
• R-Value Work: 0.179 
• R-Value Observed: 0.182 

Literature

Further insight into S-adenosylmethionine-dependent methyltransferases: structural characterization of Hma, an enzyme essential for the biosynthesis of oxygenated mycolic acids in Mycobacterium tuberculosis.

Boissier, F., Bardou, F., Guillet, V., Uttenweiler-Joseph, S., Daffe, M., Quemard, A., Mourey, L.

(2006) J Biol Chem 281: 4434-4445

• PubMed: 16356931 
• DOI: 10.1074/jbc.M510250200
• Structures With Same Primary Citation


• PubMed Abstract: 
  

Mycolic acids are major and specific components of the cell envelope of Mycobacteria that include Mycobacterium tuberculosis, the causative agent of tuberculosis. Their metabolism is the target of the most efficient antitubercular drug currently used in therapy, and the enzymes that are involved in the production of mycolic acids represent important targets for the development of new drugs effective against multidrug-resistant strains. Among these are the S-adenosylmethionine-dependent methyltransferases (SAM-MTs) that catalyze the introduction of key chemical modifications in defined positions of mycolic acids. Some of these subtle structural variations are known to be crucial for both the virulence of the tubercle bacillus and the permeability of the mycobacterial cell envelope. We report here the structural characterization of the enzyme Hma (MmaA4), a SAM-MT that is unique in catalyzing the introduction of a methyl branch together with an adjacent hydroxyl group essential for the formation of both keto- and methoxymycolates in M. tuberculosis. Despite the high propensity of Hma to proteolytic degradation, the enzyme was produced and crystallized, and its three-dimensional structure in the apoform and in complex with S-adenosylmethionine was solved to about 2 A. Thestructuresshowtheimportantroleplayedbythemodificationsfound within mycolic acid SAM-MTs, especially thealpha2-alpha3 motif and the chemical environment of the active site. Essential information with respect to cofactor and substrate binding, selectivity and specificity, and about the mechanism of catalytic reaction were derived.

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Organizational Affiliation: 

Département Mécanismes Moléculaires des Infections Mycobactériennes, Institut de Pharmacologie et de Biologie Structurale du CNRS et de l'Université Paul Sabatier, Toulouse, France

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
methoxy mycolic acid synthase 4	A	318	Mycobacterium tuberculosis H37Rv	Mutation(s): 0  Gene Names: mmaA4 (Rv0642c), mmaA4, hma, mma4, Rv0642c EC: 2.1.1
Find proteins for Q79FX8 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)) Go to UniProtKB:  Q79FX8

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
SAM	A	S-ADENOSYLMETHIONINE C15 H22 N6 O5 S MEFKEPWMEQBLKI-FCKMPRQPSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.239 
• R-Value Work: 0.179 
• R-Value Observed: 0.182 
• Space Group: P 3₁ 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 56.779	α = 90
b = 56.779	β = 90
c = 199.035	γ = 120

Software Package:

Software Name	Purpose
REFMAC	refinement
MOSFLM	data reduction
CCP4	data scaling
PHASER	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2006-01-04 
• Released Date: 2006-01-17 
Deposition Author(s): Boissier, F., Guillet, V., Mourey, L.

Revision History 

• Version 1.0: 2006-01-17
  Type: Initial release
  
• Version 1.1: 2008-05-01
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Advisory, Source and taxonomy, Version format compliance