Figure 1. Site-directed mutagenesis of the lysine residues of the dndE gene in pJTU1238.

The indicated mutations of key lysine residues (K17, K18, K20, K53, K87 and K91) were constructed in pJTU1238, a plasmid harboring the dndBCDE genes of S. enterica. The asterisks denote the selected lysine residues that were replaced with alanines. The residues marked in red indicate the amino acids that are deleted in the dndE in-frame deletion mutant.