Patent ID: 8389241

Claim:
An isolated DNA encoding a protein selected from the group consisting of (I), (J), (U), and (V), wherein said protein has an amino acid sequence defined as follows: (I) the amino acid sequence consisting of amino acid residues numbers 26 to 620 of SEQ ID NO:25, (J) an amino acid sequence which includes substitution, deletion, insertion, and/or addition, of one to 30 amino acids in the amino acid sequence consisting of amino acid residues numbers 26 to 620 of SEQ ID NO:25, and has at least 50% of the peptide-forming activity of a protein corresponding to unmutated amino acid residue numbers 26 to 620 of SEQ ID NO:25 at 50° C. and a pH of 8, (U) the amino acid sequence consisting of SEQ ID NO:25, and (V) an amino acid sequence which includes substitution, deletion, insertion, and/or addition, of one to 30 amino acids in the amino acid sequence consisting of SEQ ID NO:25, and has at least 50% of the peptide-forming activity of a protein corresponding to unmutated SEQ ID NO:25 at 50° C. and a pH of 8, or an isolated DNA selected from the group consisting of (i), (i2), and (u), wherein said DNA has a nucleotide sequence defined as follows: (i) a nucleotide sequence consisting of nucleotide numbers 104 to 1888 of SEQ ID NO:24, (i2) a nucleotide sequence that hybridizes under stringent conditions with a DNA having a nucleotide sequence complementary to a nucleotide sequence consisting of nucleotide numbers 104 to 1888 of SEQ ID NO:24 under stringent conditions, wherein said stringent conditions are 0.1×SSC and 0.1% SDS at 65° C., and encodes a protein that has at least 50% of the peptide-forming activity at 50° C. and a pH of 8 of a protein encoded by unmutated nucleotide numbers 104 to 1888 of SEQ ID NO:24, (s) a nucleotide sequence consisting of nucleotide numbers 29 to 1888 of SEQ ID NO:24.