Fig. 2.

Construction of chimeras by domain swapping and determination of FA desaturase activities. A, B: Schematic structural diagrams of the WT desaturase and chimeric proteins constructed by domain swapping. C, E: Autoradiogram of the products of [¹⁴C]palmitate labeling of B. subtilis LC5 derivative strains expressing the WT and recombinant proteins. EV represents the B. subtilis LC5 strain carrying the empty vector. Cells were grown overnight at 37°C in MM, washed, resuspended in fresh MM, with or without xylose 0.5%, and labeled with 1 μCi/ ml of [¹⁴C]palmitate for 3 h at 37°C. FAs were converted to FAMEs and analyzed using 10% silver nitrate-impregnated Silica Gel G plates. The radioactivity on the plates was visualized using a PhosphorImager screen. SFA, saturated fatty acids. D, F: Total UFAs, expressed as proportion (%) of the total FAs, quantified by GC/MS. Data represent means ± SD of three replicate cultures.