A386S
possibly critical role in catalysis, relative activity: 90% (wild-type: 100%)
A41E
possibly critical for sugar binding, relative activity: 0% (wild-type: 100%)
Y250F
possibly important for substrate specificity (galacturonic acid /glucuronic acid), relative activity: 90% (wild-type: 100%), 50% activity with D-glucuronic acid (wild-type: 0%)