FIG. 2.
Nucleotide hydrolysis activity of wild-type (WT) and mutant FlhF proteins. Released phosphate from [γ-32P]GTP or [γ-32P]ATP was monitored in reactions with purified wild-type and FlhF mutant proteins over 30 min. FlhF proteins and nucleotides were used at final concentrations of 0.5 μM and 0.1 μM, respectively. Hydrolysis activity is expressed as the percentage of labeled phosphate released compared to the amount of labeled phosphate in nonhydrolyzed nucleotides remaining at each time point. Data presented are from a representative assay. Closed symbols indicate phosphate released from GTP with addition of WT FlhF (♦), FlhF(K295A) (▴), FlhF(D321A) (×), FlhF(R324A) (▪), and FlhFΔG (•). Open symbols indicate phosphate released from ATP with addition of WT FlhF (⋄).