Mycobacterium tuberculosis arabinosyltransferase (AraT)

Mycobacterium tuberculosis arabinosyltransferases are a family of membrane-associated enzymes essential for the assembly of the complex mycobacterial cell wall. This family includes the Emb proteins (EmbA, EmbB, and EmbC) and the Aft proteins (AftA, AftB, AftC, and AftD), which catalyze the transfer of arabinofuranose from the donor decaprenylphosphoryl-arabinose to the arabinan domains of arabinogalactan and lipoarabinomannan [1, 3, 12]. These polysaccharides form a critical structural barrier that protects the bacterium from environmental stress and antibiotics [2, 20]. The first-line antitubercular drug ethambutol targets the Emb proteins, specifically inhibiting their activity and leading to cell wall disruption and bacterial death [3, 4, 8]. Resistance to ethambutol is frequently associated with mutations in the embB gene, making these enzymes a focal point for monitoring drug efficacy and developing new therapeutic strategies against multidrug-resistant tuberculosis [3, 9, 16].

Other names

Arabinofuranosyltransferase [2, 6, 12]Emb proteins (EmbA, EmbB, EmbC) [3, 11, 15]Aft proteins (AftA, AftB, AftC, AftD) [7, 12]EmbCAB complex [4, 11]

Inhibition of arabinosyltransferase activity, which prevents the polymerization of arabinose into the cell wall polysaccharides arabinogalactan and lipoarabinomannan, leading to increased cell wall permeability and bacterial growth inhibition [3, 4, 9, 13].