FIGURE 2.

Construction of chimeras. A, proposed topology model for Momordica FADX. H1, H2, and H3 depict the location of conserved histidine boxes and are shown coordinating to a putative diiron center. Seven cleavage sites where the portions of Momordica FADX were replaced with the corresponding Arabidopsis FAD2 sequences have been marked on the model. B, schematic of chimeric enzyme sequences of Momordica FADX and Arabidopsis FAD2. Regions in white boxes originate from Momordica FADX, and regions in black boxes from Arabidopsis FAD2. For detailed description of the chimeras, see “Experimental Procedures.” C, amino acid sequence alignment of putative transmembrane helix 2 and first histidine box of Arabidopsis FAD2 and Momordica FADX. Six residues that differ between the two have been underlined.