Covering: up to November 2006

The cell envelope of Mycobacterium tuberculosis (Mtb) is a treasure house of a variety of biologically active molecules with fascinating architectures. The decoding of the genetic blueprint of Mtb in recent years has provided the impetus for dissecting the metabolic pathways involved in the biosynthesis of lipidic metabolites. The focus of this Highlight is to emphasize the functional role of polyketide synthase (PKS) proteins in the biosynthesis of complex mycobacterial lipids. The catalytic as well as mechanistic versatility of PKSs in generating metabolic diversity and the significance of recently discovered fatty acyl-AMP ligases in establishing “biochemical crosstalk” between fatty acid synthases (FASs) and PKSs is described. The phenotypic heterogeneity and remodeling of the mycobacterial cell wall in its aetiopathogenesis is discussed.