PMID- 16356931
OWN - NLM
STAT- MEDLINE
DCOM- 20060328
LR  - 20131121
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 281
IP  - 7
DP  - 2006 Feb 17
TI  - Further insight into S-adenosylmethionine-dependent methyltransferases:
      structural characterization of Hma, an enzyme essential for the biosynthesis of
      oxygenated mycolic acids in Mycobacterium tuberculosis.
PG  - 4434-45
AB  - 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.
FAU - Boissier, Fanny
AU  - Boissier F
AD  - Departement Mecanismes Moleculaires des Infections Mycobacteriennes, Institut de 
      Pharmacologie et de Biologie Structurale du CNRS et de l'Universite Paul
      Sabatier, Toulouse, France
FAU - Bardou, Fabienne
AU  - Bardou F
FAU - Guillet, Valerie
AU  - Guillet V
FAU - Uttenweiler-Joseph, Sandrine
AU  - Uttenweiler-Joseph S
FAU - Daffe, Mamadou
AU  - Daffe M
FAU - Quemard, Annaik
AU  - Quemard A
FAU - Mourey, Lionel
AU  - Mourey L
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20051215
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Bacterial Proteins)
RN  - 0 (Mycolic Acids)
RN  - 7LP2MPO46S (S-Adenosylmethionine)
RN  - EC 1.- (Mixed Function Oxygenases)
RN  - EC 1.14.18.- (mma4 protein, Mycobacterium tuberculossis)
RN  - EC 2.1.1.- (Methyltransferases)
SB  - IM
MH  - Amino Acid Sequence
MH  - Bacterial Proteins/*chemistry
MH  - Binding Sites
MH  - Crystallization
MH  - Methyltransferases/*chemistry
MH  - Mixed Function Oxygenases/*chemistry
MH  - Molecular Sequence Data
MH  - Mycobacterium tuberculosis/*enzymology
MH  - Mycolic Acids/*metabolism
MH  - Protein Structure, Tertiary
MH  - S-Adenosylmethionine/*metabolism
EDAT- 2005/12/17 09:00
MHDA- 2006/03/29 09:00
CRDT- 2005/12/17 09:00
PHST- 2005/12/17 09:00 [pubmed]
PHST- 2006/03/29 09:00 [medline]
PHST- 2005/12/17 09:00 [entrez]
AID - M510250200 [pii]
AID - 10.1074/jbc.M510250200 [doi]
PST - ppublish
SO  - J Biol Chem. 2006 Feb 17;281(7):4434-45. doi: 10.1074/jbc.M510250200. Epub 2005
      Dec 15.