Rv3389C from Mycobacterium tuberculosis, a member of the (R)-specific hydratase/dehydratase family.

Abstract

The (R)-specific 3-hydroxyacyl dehydratases/trans-enoyl hydratases are key proteins in the biosynthesis of fatty acids. In mycobacteria, such enzymes remain unknown, although they are involved in the biosynthesis of major and essential lipids like mycolic acids. First bioinformatic analyses allowed to identify a single candidate protein, namely Rv3389c, that belongs to the hydratases 2 family and is most likely made of a distinctive asymmetric double hot dog fold. The purified recombinant Rv3389c protein was shown to efficiently catalyze the hydration of (C(8)-C(16)) enoyl-CoA substrates. Furthermore, it catalyzed the dehydration of a 3-hydroxyacyl-CoA in coupled reactions with both reductases (MabA and InhA) of the acyl carrier protein (ACP)-dependent M. tuberculosis fatty acid synthase type II involved in mycolic acid biosynthesis. Yet, the facts that Rv3389c activity decreased in the presence of ACP, versus CoA, derivative and that Rv3389c knockout mutant had no visible variation of its fatty acid content suggested the occurrence of additional hydratase/dehydratase candidates. Accordingly, further and detailed bioinformatic analyses led to the identification of other members of the hydratases 2 family in M. tuberculosis.

• Authors: Emmanuelle Sacco, Virginie Legendre, Françoise Laval, Didier Zerbib, Henri Montrozier, Nathalie Eynard, Christophe Guilhot, Mamadou Daffé, Annaïk Quémard
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 1774 Issue 2 Pg. 303-11 (Feb 2007) ISSN: 0006-3002 [Print] Netherlands
• PMID: 17240207 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Bacterial Proteins

Topics

• Amino Acid Sequence
• Bacterial Proteins (chemistry)
• Catalysis
• Models, Molecular
• Molecular Sequence Data
• Mycobacterium tuberculosis (chemistry, enzymology)
• Sequence Homology, Amino Acid
• Spectrometry, Mass, Electrospray Ionization
• Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization