Nucleic Acids Symposium Series · 2003 · 12 citations · 0 references
Life SciencesBiochemistryMicrobiologyDirected EvolutionEnzymologyMolecular EvolutionDirected Evolution Of EnzymesEnzyme EvolutionEnzyme KineticsMolecular Evolution In MicrobesStrain ImprovementActivitiesAlkaliphilic MicrobiologyPh DependencePh OptimaProtein Evolution In MicrobesXylanase Activity
Alkaliphilic Bacillus sp. strain 41M-1 produces an alkaliphilic xylanase (xylanase J). The newly constructed mutant E177Q deltaJC had an acidic pH optimum and showed almost no activity at pH 8.0. The alkaliphily of the enzyme was restored by directed evolution. The evolved mutants, Y176S/E177Q deltaJC and G32V/Y176D/E177Q deltaJC, retained about 30% and 43% activity of their maximal activities at pH 6.0, respectively.