| 摘要 |
PROBLEM TO BE SOLVED: To obtain an extreme thermostable chitinase comprising an extreme thermostable chitinase (modified substance) containing a specific amino acid sequence, having a chitin hydrolyzing action, produced by a host cell using a gene isolated from an extreme thermophilic archaebacterium. SOLUTION: An extreme thermostable chitinase contains an amino acid sequence of the formula or a new extreme thermostable chitinase comprises its modified substance containing an amino acid sequence in which one or plural amino acids are deleted, substituted or added in the amino acid sequence of the formula and having chitinase activity, is a chitin hydrolyzing enzyme, has a controlling function of pathogenic microorganisms in a plant and can develop a plant having disease tolerance. The extreme thermostable chitinase is obtained by isolating a DNA encoding extreme thermostable chitinase from an extreme thermophilic archaebacterium KOD-1 strain, transferring the DNA to a host cell and culturing the DNA. |
