| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject enzyme, capable of amplifying the total length of a template DNA chain without terminating the elongation of a synthetic chain in the course thereof and useful for in vitro synthesis or amplification, determination of a base sequence, etc., of the DNA chain when synthesizing and amplifying the DNA chain having a specific amino acid sequence according to a polymerase chain reaction(PCR), etc. SOLUTION: This thermostable DNA synthase has an amino acid sequence represented by the formula without terminating the elongation of a synthetic chain when catalyzing the synthesis of a DNA chain complementary to a single- stranded DNA. The synthase is obtained by carrying out a genetic engineering modification of a Pfu DNA synthase derived from Pyrococcus furiosus according to a well-known method for preparing a mutant gene. The mutant gene of the Pfu DNA synthase gene is then cloned to a recombinant plasmid pDP320, transferred into Escherichia coli HMS174 (DE3) and deposited as FERM P-16052. |
