FIG. 3.

Enzyme activity and expression levels of native NodZ and mutants. NodZ was mutated at positions indicated in the legend to Fig. 1. The yield of recombinant protein was determined by Western blotting after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (lower panel). Cell extracts were adjusted to give equivalent amounts of native and mutant enzymes for enzyme assays. Fucosyltransferase activity of mutants (gray bars) is expressed relative to the native enzyme (black bar). Values are the averages of at least three determinations.