To investigate the thermostability and its thermostable mechanism of Xyn10A from Thermotoga thermarum DSM 5069,protein structure modeling and site-directed mutagenesis were carried out in this study to find out the domain involved in the Ca~(2+)binding in the Xyn10A.Then we tried to obtain mutants with better stability by mutating some amino acids of the Ca~(2+)binding domain.Furthermore,the catalytic residues were also confirmed by the site-directed mutagenesis of key amino acids in the catalytic domain of...