Fig. 4: Deletion of both aliA and aliB led to complete absence of thioether-linked archaeol from lipoprotein extracts.

a Representative merged extracted ion chromatograms (EICs) (m/z values in methods) showing the presence of saturated and unsaturated diether core lipids (archaeols) in base hydrolyzed biomass from the wild-type and ΔaliA/ΔaliB strains. b Average (n = 3) relative abundance of the saturated and unsaturated diether core lipid species found in wild-type and ΔaliA/ΔaliB strains. c Representative merged EICs (m/z = 683.7, 700.8, and 705.7, corresponding to the protonated, ammoniated, and sodiated adducts of methylthio-archaeol) showing that the synthesized methylthio-archaeol standard is readily detectable with our methods and that the same methylthio-archaeol compound is detected in extracts from methyl iodide treated lipoproteins from the wild type, while methylthio-archaeol is notably absent in that from the ΔaliA/ΔaliB strain. Note that the y-axis of the EIC for the ΔaliA/ΔaliB strain is shown two orders of magnitude zoomed in compared to the wild type. d Bar chart showing the average mass of methylthio-archaeol recovered from methyl iodide treated lipoproteins per milligram of starting protein, based on three biological replicates. An average of 3.20 ng +/− 0.62 ng of methylthio-archaeol per milligram of protein was recovered from the wild type, while no methylthio-archaeol was recovered from the ΔaliA/ΔaliB strain. Error bars represent standard deviations.