Patent ID: 6713281
Filing Date: 2004-03-30
Classification: C12N,C12Y

Abstract:
A method of producing a thermostable enzyme which is stable at temperatures of at least 60Â° C. and which exhibits higher activity at a desired lower temperature below 60Â° C., compared with a corresponding wild-type enzyme at its optimal temperature, comprising:(a) isolating nucleic acid from a thermophilic organism, said nucleic acid comprising at least one polynucleotide encoding a desired enzyme which is stable at a temperature of at least 60Â° C.; (b) preparing a library of clones generated from the nucleic acid of step (a); (c) mutating the nucleic acid sequence contained in a clone from the library comprising the at least one polynucleotide of step (a); and (d) screening mutants produced by the mutating step (c) to identify a mutated enzyme or a polynucleotide encoding a mutated enzyme, wherein the mutated enzyme is stable at a temperature of at least 60Â° C., and has increased enzyme activity at a lower temperature than the activity of the corresponding wild-type enzyme at its optimal temperature.