FIG 1 .

IlvE activity is inhibited by serine and IlvA. IlvE assays were performed using a radioactive assay as described in Materials and Methods. (A) IlvE assays were performed in the presence of IlvA, serine (Ser), pyruvate (Pyr), or threonine (Thr), as indicated. (B) RidA homologs were added to IlvE that had been preincubated with IlvA and serine (Ser), as indicated. RidA homologs tested were from S. enterica (S.e.), P. furiosus (P.f.), C. sativus (C.s.), and H. sapiens (H.s.). Shown are averages and ranges from two replicates for each condition (ranges, ≤1 in all cases). Each assay was performed independently at least twice.