Figure 1: MS of lipid profiles of wild type, mce1 operon mutant and its complemented strain. (A) Total lipid extracts from wild type M. tuberculosis H37Rv (top), ?mce (middle), and complemented strain ?mce::mce (bottom). The lipids were found to accumulate in the m/z 1100-1300 range in the ?mce, but not the wild-type or complemented strain (insets). (B) A hexane extraction localized the accumulating lipids to the outer surface of the cell. M. tuberculosis H37Rv (top), ?mce1 (middle), and ?mce1::mce1 (bottom). Zoom of the m/z 1100-1300 region.