Pseudouridine incorporation measured with various hPus1p enzymes.

aThe activities are in moles ψ/moles RNA with the mean of three separate assays and standard deviation (SD). With all of the substrates the maximum activity should be ∼1.0 moles ψ/moles RNA. Background levels of activity seen with Lac (β-galactosidase) have been subtracted. ND indicates that the combination of D146A ΔhPus1p D146A and the corresponding RNA substrate was not determined.