Fig. 3. Rv0455c is required for siderophore secretion by M. tuberculosis.

Thin-layer chromatography of chloroform-extracted siderophores from the culture filtrates of the M. tuberculosis mc²6230 parent strain, the siderophore biosynthetic mutant ΔmbtD, the siderophore secretion-defective mutant ΔmmpS4/mmpS5, the Δrv0455c mutant and the Δrv0455c mutant complemented with integrated rv0455c and rv0455c-TM3 expression vectors. The siderophores were labeled with [7-¹⁴C]-salicylic acid (SA), which was loaded on the silica gel plate as a control together with ⁵⁵Fe-carboxymycobactin (cMBT) and ⁵⁵Fe-mycobactin (MBT). A mixture of ethanol/cyclohexane/water/ethyl acetate/acetic acid with the volume ratios of 5:25:2.5:35:5⁴² was used as a solvent. The loaded samples were normalized to their OD₆₀₀ at the time of harvest of the bacterial cultures. Data were obtained from at least two independent experiments and representative images are shown. Source data are provided in the Source Data file.