FIG 2 .
3CA inhibits both wild-type IlvE and IlvEE38A activity. IlvE assays were performed with pure protein using DNPH derivatization and subsequent organic extraction to quantify the product 2KMV as described in Materials and Methods. Wild-type IlvE and IlvEE38A were assayed in the absence and presence of the inhibitor 3CA and RidA as indicated. Shown are averages and ranges from two replicates for each condition (ranges, ≤1 in all cases). Each assay was performed independently at least twice.