Patent ID: 11407987

Abstract:
The present invention relates to a mannanase PMan5A mutant having improved heat resistance, a gene encoding the mutant and application thereof. The mutant is obtained by a substitution of histidine with tyrosine at amino acid residue 93, phenylalanine with tyrosine at amino acid residue 94, leucine with histidine at amino acid residue 356, and/or alanine with proline at amino acid residue 389. The thermal tolerance of the single site mutation mutant H93Y, L356H and A389P are greatly improved over that of the wild-type mannanase PMan5A, and the thermal tolerance of the combination mutants shows the stack effect of the single site mutation, demonstrating the amino acids at the sites of 93, 94, 356, and 389 play an important role for the thermal stability of the mannanase of GH5 family.