(1 } 3, 1 } 4)- beta -GLUCANASE OF ENHANCED STABILITY

摘要

This invention relates to a (1 } 3, 1 } 4)- beta -glucanase (glucanase EII endohydrolase) enzyme, whose amino acid sequence has been modified in order to provide an enzyme whose three-dimensional structure confers improved thermostability and/or pH stability. Specific modifications are based upon a comparison between the three-dimensional structure of (1 } 3, 1 } 4)- beta -glucanase and that of (1 } 3)- beta -glucanase. The (1 } 3, 1 } 4)- beta -glucanase gene has been modified by site-directed mutagenesis, and modified enzymes have been expressed in Escherichia coli. Modified sequences, DNA molecules encoding them, plasmids, expression vectors and transgenic plants are disclosed and claimed.