Method for using heat-resistant mismatch endonuclease
Provided are a mismatch-specific cleavage reaction using a novel heat-resistant mismatch nuclease, a method for removing errors in a nucleic acid amplification reaction using the mismatch nuclease, a method for inhibiting the amplification of a nucleic acid having a specific base sequence during a nucleic acid amplification reaction, and a method for detecting a nucleic acid having a single-base polymorphic mutation using this inhibition method.
1. A method of cleaving a double-stranded nucleic acid, the method comprising:
treating a double-stranded nucleic acid having a mismatched base pair with at least one polypeptide selected from the group consisting of the following (i) to (iii) to cleave both strands of the double-stranded nucleic acid at the position of the mismatched base pair,
(i) a polypeptide having an amino acid sequence of SEQ ID NO:1;
(ii) a polypeptide having an amino acid sequence which differs from the amino acid sequence of SEQ ID NO:1 by substitution, deletion, insertion and/or addition of 1 to 10 amino acid residues, and having a mismatch endonuclease activity; and
(iii) a polypeptide having an amino acid sequence which shares at least 75% amino acid sequence identity with the amino acid sequence of SEQ ID NO:1, and having a mismatch endonuclease activity,
wherein the double-stranded nucleic acid is generated during a nucleic acid amplification process, and the cleaving is performed during or after the nucleic acid amplification process, and
wherein the nucleic acid amplification process is performed by a polymerase chain reaction (PCR) method, a multiple displacement amplification (MDA) method or an isothermal nucleic acid amplification method.
2. The method according to claim 1 , wherein the mismatched base pair comprises contiguous 1 to 8 mismatched base pairs existing between two base pairs which are normally paired on the double-stranded nucleic acid.