Mycobacterial arabinosyl transferase (null)

Mycobacterial arabinosyl transferases are a group of membrane-bound enzymes essential for the biosynthesis of the mycobacterial cell wall. They catalyze the polymerization and attachment of arabinan chains onto galactan backbones to form arabinogalactan—a critical structural component that links peptidoglycan with mycolic acids. This process is vital for maintaining cell wall integrity and viability in pathogenic species such as *Mycobacterium tuberculosis*. The best-characterized members include AftA (priming enzyme), EmbA, EmbB, and EmbC. These enzymes are clinically significant because they are targeted by first-line anti-tuberculosis drugs like ethambutol; inhibition disrupts cell wall synthesis leading to bacteriostasis. Mutations conferring resistance not only reduce drug efficacy but may also contribute to multidrug-resistant TB phenotypes. Structural studies reveal that these enzymes possess a conserved glycosyltransferase-C fold and function as dimers within the membrane environment[1][3][4].

Other names

ArabinosyltransferaseArabinofuranosyltransferaseEmbA, EmbB, EmbC (gene products encoding different isoforms in Mycobacterium tuberculosis)

Inhibition of arabinosyl transferase by ethambutol blocks the synthesis of the major cell wall polysaccharide arabinogalactan, halting bacterial growth and leading to bacteriostasis[3][4].