| 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 (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 E. coli. Modified sequences, DNA molecules encoding them, plasmids, expression vectors and transgenic plants are disclosed.
|
