Journal Article

Identification, cloning, purification, and enzymatic characterization of Mycobacterium tuberculosis 1-deoxy-d-xylulose 5-phosphate synthase

Ann Marie Bailey, Sebabrata Mahapatra, Patrick J. Brennan and Dean C. Crick

in Glycobiology

Published on behalf of Society for Glycobiology

Volume 12, issue 12, pages 813-820
Published in print December 2002 | ISSN: 0959-6658
Published online December 2002 | e-ISSN: 1460-2423 | DOI: https://dx.doi.org/10.1093/glycob/cwf100
Identification, cloning, purification, and enzymatic characterization of Mycobacterium tuberculosis 1-deoxy-d-xylulose 5-phosphate synthase

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The enzyme encoded by Rv2682c in Mycobacterium tuberculosis is a functional 1-deoxy-d-xylulose 5-phosphate synthase (DXS), suggesting that the pathogen utilizes the mevalonate-independent pathway for isopentenyl diphosphate and subsequent polyprenyl phosphate synthesis. These key precursors are vital in the biosynthesis of many essential aspects of the mycobacterial cell wall. Rv2682c encodes the conserved DRAG sequence that has been proposed as a signature motif for DXSs and also all 13 conserved amino acid residues thought to be important to the function of transketolase enzymes. Recombinant Rv2682c is capable of utilizing glyceraldehyde 3-phosphate and erythrose 4-phosphate as well as d- and l-glyceraldehyde as aldose substrates. The enzyme has Km values of 40 µM, 6.1 µM, 5.6 mM, and 4.5 mM for pyruvate, d-glyceraldehyde 3-phosphate, d-glyceraldehyde, and l-glyceradehyde, respectively. Rv2682c has an absolute requirement for divalent cation and thiamin diphosphate as cofactors. The Kd thiamin diphosphate for the native M. tuberculosis DXS activity partially purified from M. tuberculosis cytosol is 1 µM in the presence of Mg2+.

Keywords: Key words: glyceraldehyde/isopentenyl diphosphate synthesis/pyruvate/transketolase

Journal Article.  5633 words.  Illustrated.

Subjects: Carbohydrates

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