Figure 3.
Substrate specificity profiles of the wild-type castor Δ9-18:0-ACP DES (A) and mutants of this enzyme obtained from substrate-dependent selection by E. coli MH13/pAnFd cells (B–I). Shown are the specific activities of purified recombinant enzymes with 14:0-, 16:0-, and 18:0-ACP. Mutants of the castor Δ9-18:0-ACP DES were selected from libraries containing random mutations at codons for amino acids 114, 118, 179, or 188 as well as both amino acids 114 and 188 as described in the text. Activities are shown for the wild-type DES (A) as well as mutants G188L (B), M114I/G188L (C), L118W (D), L118Y (E), L118F (F), M114I (G), M114F (H), and P179I (I).