Glycopeptidolipid acetylation affects sliding motility and biofilm formation in Mycobacterium smegmatis

The absence of glycopeptidolipids (GPLs) abolishes the ability of mycobacteria both to slide over the surface of motility plates and to form biofilms on polyvinyl chloride. In a screen for biofilm-defective mutants of Mycobacterium smegmatis mc(2) 155, a new mutant was obtained that resulted in partial inhibition of both processes and also showed an intermediate rough colony morphology. The mariner transposon insertion mapped to a GPL biosynthesis gene (atf1) which encodes a putative acetyltranferase involved in the transfer of acetyl groups to the glycopeptide core. Physical characterization of the GPLs from the atf1 mutant demonstrated that they were not acetylated.