Lipoarabinomannan of Mycobacterium: mannose capping by a multifunctional terminal mannosyltransferase.

ABSTRACT: Biosynthesis of phosphatidylinositol (PI)-containing lipoarabinomannan (LAM) and lipomannan (LM) of Mycobacterium spp. follows a conserved pathway involving multiple membrane-associated, substrate-specific mannosyltransferases (ManTs) responsible for the sequential addition of alpha-mannopyranosyl (Manp) units donated by decaprenyl-P-Manp on the periplasmic side of the plasma membrane. Because of their receptor-binding and immunomodulatory properties, the alpha(1-->2)-linked di- and tri-Manp motifs that functionalize the nonreducing arabinan termini of LAM (ManLAM) in Mycobacterium tuberculosis are of crucial importance. We now show that the M. tuberculosis ManT, Rv2181, is required for the addition of these alpha(1-->2)-linked Manp residues but also at other locations of the LAM molecule.

SUBMITTER: Kaur D 

PROVIDER: S-EPMC2584715 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature