CLONED DNA POLYMERASES FROM THERMOTOGA NEAPOLITANA AND MUTANTS THEREOF

摘要

The invention relates to a substantially pure thermostable DNA polymerase from Thermotoga neapolitana (Tne) and mutants thereof. The Tne DNA polymerase has a molecular weight of about 100 kilodaltons and is more thermostable than Taq DNA polymerase. The mutant Tne DNA polymerase has at least one mutation selected from the group consisting of (1) a first mutation that substantially reduces or eliminates 3' 5' exonuclease activity of said DNA polymerase; (2) a second mutation that substantially reduces or eliminates 5' 3' exonuclease activity of said DNA polymerase; (3) a third mutation in the O helix of said DNA polymerase resulting in said DNA polymerase becoming non-discriminating against dideoxynucleotides. The present invention also relates to the cloning and expression of the wild type or mutant Tne DNA polymerase in E. coli, to DNA molecules containing the cloned gene, and to host cells which express said genes. The Tne DNA polymerase of the invention may be used in well-known DNA sequencing and amplification reactions.