Fig. 4.
Phenotypic analysis of the M. smegmatis ΔaccD6 mutant. (A) Growth rate analysis of wild-type M. smegmatis (curve 1), the ΔaccD6 mutant (curve 2), and strains complemented with intact copies of accD6Msm and accD6Mtb expressed under the control of the acetamidase promoter: the ΔaccD6Msm-Pami-accD6Msm (curve 3) and ΔaccD6Msm-Pami-accD6Mtb (curve 4) strains. Growth rate analysis was performed on Sauton medium, and OD values are means ± standard errors from three independent experiments. (B) Western blot of total crude lysates from the M. smegmatis wild-type strain (lane 1) and the ΔaccD6Msm-Pami-accD6Mtb mutant grown in the absence (−) or presence (+) of acetamide (lane 2). (C) Thin-layer chromatography of 14C-labeled FAMEs and MAMEs extracted from wild-type M. smegmatis (lane 1), the ΔaccD6 mutant (lane 2), and the uninduced (−) and induced (+) ΔaccD6Msm-Pami-accD6Mtb mutant (lane 3). Equal counts (100,000 cpm) were loaded onto a TLC plate and were separated as described in Materials and Methods. The symbols α, α′, and e correspond to α-mycolates, α′-mycolates, and epoxy-mycolates, respectively.