Cloning, expression and characterization of Mycobacterium tuberculosis lipoprotein LprF

Lipoproteins are well known Virulence factors of bacterial pathogens in general and of Mycobocterium tuberculosis (Mtb), the causative agent of tuberculosis, in particular Lipoprotein lipidation between Gram-positive and Gram-negative bacteria differs significantly as these are di- and triacylated, respectively Little is known about the lipid anchor Of mycobacterial lipoproteins. We reported recently that mycobacterial LppX. a lipoprotein involved in synthesis of cell wall components is triacylated, although mycobacteria are classified as GC-rich Gram-positive bacteria We here exploited the model organism Mycobacterium smegmatis for the expression of Mtb LprF and characterized N-terminal modifications at the molecular level. LprF is a putative lipoprotein of Mtb involved in signaling of potassium-dependent osmotic stress LprF is extensively modified in a mycobacterium-specific manner by a thioether-linked diacylglyceryl residue with one ester-bound tuberculostearic- and one C16 0 fatty acid and additionally by a third N-linked C16:0 fatty acid, and a hexose (C) 2009 Elsevier Inc. All rights reserved