Chimeric DNA polymerases
The present invention provides, among other things, chimeric DNA polymerases containing heterologous domains having sequences derived from at least two DNA polymerases that have at least one distinct functional characteristics (e.g., elongation rate, processivity, error rate or fidelity, salt tolerance or resistance) and methods of making and using the same. In some embodiments, the present invention can combine desired functional characteristics (e.g., high processivity; high elongation rate; thermostability; resistance to salt, PCR additives (e.g., PCR enhancers) and other impurities; and high fidelity) of different DNA polymerases in a chimeric polymerase.
1. A DNA polymerase whose amino acid sequence contains, in order:
an N-terminal domain including a sequence that shows at least 90% identity with that sequence between residues 26 and 105 of SEQ ID NO: 16;
an exonuclease
domain including a sequence that shows at least 90% identity with that sequence between residues 156 and 301 of SEQ ID NO: 16;
a palm and finger
domain including a sequence that shows at least 90% identity with that sequence between residues 394 and 563 of SEQ ID NO: 16; and
a thumb domain including a sequence that shows at least 90% identity with that sequence between residues 612 and 749 of SEQ ID NO: 16.
2. A kit comprising a DNA polymerase of claim 1 .
3. A method of DNA synthesis using the DNA poiymerase of claim 1 comprising combining the DNA polymerase, template DNA, primer(s) and nucleotides and incubating under conditions for DNA synthesis.
4. A method of amplifying a DNA fragment using the DNA polymerase of claim 1 comprising combining the DNA polymerase, a DNA fragment, primer(s) and nucleotides and incubating under conditions for DNA amplification.