MANNANASE PMAN5A MUTANT HAVING IMPROVED HEAT RESISTANCE, GENE THEREOF, AND APPLICATION

摘要

The present invention relates to mannanase PMan5A mutant having improved heat resistance, gene and application thereof. Said mutant is obtained by substitution the 93^th histidine with tyrosine, the 94^th phenylalanine with tyrosine, the 356^th leucine with histidine, and/or the 389^th alanine with proline. The thermal tolerance of the single site mutation mutant H93Y, L356H and A389P are greatly improved over that of the wild 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 the important role for the thermal stability of the mannanase of GH5 family.