Just like lipoarabinomannan (map00571), arabinogalactan (AG) is a major heteropolysaccharide found on the mycobacterium cell wall. AG consists of a linear galactan chain of galactofuranosyl (Galf) residues covalently connected to peptidoglycan (PG), with branches of three similar arabinan chains comprising arabinofuranosyl (Araf) residues. The non-reducing ends of arabinans are often covalently attached to the long fatty acids of mycolic acids. Thus, the covalently linked network of PG and mycolylated AG, termed the mycolyl-arabinogalactan-peptidoglycan (mAGP) complex, forms an exceptionally robust cell wall and provides a permeability barrier to antibiotics.
Grzegorzewicz AE, de Sousa-d'Auria C, McNeil MR, Huc-Claustre E, Jones V, Petit C, Angala SK, Zemanova J, Wang Q, Belardinelli JM, Gao Q, Ishizaki Y, Mikusova K, Brennan PJ, Ronning DR, Chami M, Houssin C, Jackson M
Title
Assembling of the Mycobacterium tuberculosis Cell Wall Core.
Detailed structural and quantitative analysis reveals the spatial organization of the cell walls of in vivo grown Mycobacterium leprae and in vitro grown Mycobacterium tuberculosis.
