Patent ID: 8329428

Claim:
An isolated DNA encoding a protein selected from the group consisting of (G), (H), (S), and (T), wherein said protein has an amino acid sequence defined as follows: (G) the amino acid sequence consisting of amino acid residues numbers 23 to 645 of SEQ ID NO:23, (H) 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 23 to 645 of SEQ ID NO:23, and has at least 50% of the peptide-forming activity of a protein corresponding to unmutated amino acid residue numbers 23 to 645 of SEQ ID NO:23 at 50° C. and a pH of 8, (S) the amino acid sequence consisting of SEQ ID NO:23, and (T) 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:23, and has at least 50% of the peptide-forming activity of a protein corresponding to unmutated SEQ ID NO:23 at 50° C. and a pH of 8, or an isolated DNA selected from the group consisting of (g), (g2), and (s), wherein said DNA has a nucleotide sequence defined as follows: (g) a nucleotide sequence consisting of nucleotide numbers 127 to 1995 of SEQ ID NO:22, (g2) a nucleotide sequence that hybridizes under stringent conditions with a DNA having a nucleotide sequence complementary to a nucleotide sequence consisting of nucleotide numbers 127 to 1995 of SEQ ID NO:22 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 unmutatetd nucleotide numbers 127 to 1995 of SEQ ID NO:22, (s) a nucleotide sequence consisting of nucleotide numbers 61 to 1995 of SEQ ID NO:22.