Definition of the full extent of glycosylation of the 45-kilodalton glycoprotein of Mycobacterium tuberculosis

The Thr residues of the 45-kilodalton (kDa) glycoprotein of Mycobacterium tuberculosis containing an alpha-D-Man, mannobiose or mannotriose unit are universally O-glycosylated. The glycosylation sites are present in the Pro-rich areas of the N- and C-terminal of the mature 45-kDa glycoprotein. The Pro residues increase glycosylation by increasing the recognition of Thr residues by glycosyltransferase. Glycosylation makes the glycoprotein stiff and extended in conformation. This is probably necessary for targeting glycoproteins to the external environment.