[Novel mechanism of 3' exonuclease of polymerase in maintenance of DNA replication fidelity and its application in SNP assay].
Polymerase with 3' to 5'exonulcease plays an important role in the maintenance of in vivo DNA replication fidelity. In order to develop more reliable SNP assays, we revisit the underlying molecular mechanisms by which DNA polymerases with 3' exonucleases maintain high fidelity of DNA replication. In addition to mismatch removal by proofreading, we recently discovered a premature termination of polymerization by a new mechanism of OFF-switch. This novel ON/OFF switch turns off DNA polymerization from mismatched primers and turns on DNA polymerization from matched primers. Two SNP assays were developed based on the proofreading and the newly identified OFF-switch respectively: terminal labeled primer extension and the ON/OFF switch operated SNP assay. These two new methods are well adapted to conventional techniques such as electrophoresis, real time PCR, microplates, and microarray. Application of these reliable SNP assays will greatly facilitate genetic and biomedical studies in the post-genome era.
Chen
Lin-Ling
LL
Genomapping Inc, Tianjin 300192, China.
Zhang
Jia
J
Peng
Cui-Ying
CY
Liao
Duan-Fang
DF
Li
Hong-Jian
HJ
Gao
Han-Lin
HL
Li
Kai
K
D017931:DNA Primers; D004261:DNA Replication; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D005092:Exonucleases / Q000378:metabolism*; D005821:Genetic Techniques; D008957:Models, Genetic; D020641:Polymorphism, Single Nucleotide
D017931:DNA Primers; D004259:DNA-Directed DNA Polymerase; D005092:Exonucleases