Figure 1: Arabinogalactan motif of Mycobacterium tuberculosis cell wall.

Arabinan is attached at the C-5 position of the galactan. Both arabinose and galactose are in the furanosyl form. Galf(1→6)Galf linkages and Araf(1→3 or 5)Araf linkages are all in the 1,2-trans manner, whereas Araf(1→2)Araf linkages are 1,2-cis mannered.