FIGURE 3.

Use of fluorescent primers to monitor the reaction products of single point mutant enzymes. Reaction profiles of the monofunctional mutants NmW-(E307A)-His₆ and NmW-(S972A)-His₆ were recorded in the presence of both donor sugars using the fluorescent primers as indicated. Reaction samples were taken after 15 s and 30 min. Peaks marked in gray represent 4-MU-DP1 and are unmodified in all reactions. A, NmW-(E307A)-His₆ with 4-MU-DP2. The only reaction product formed was 4-MU-DP3. B, NmW-(E307A)-His₆ primed with 4-MU-DP3. No product was formed. C, NmW-(S972A)-His₆ primed with 4-MU-DP2. No product was formed. D, NmW-(S972A)-His₆ primed with 4-MU-DP3. The only product formed was 4-MU-DP4.