Exonuclease processivity of archaeal replicative DNA polymerase in association with PCNA is expedited by mismatches in DNA
| Autor: | Sonoko Ishino, Hirokazu Nishida, Toshiyuki Tsuji, Yoshizumi Ishino, Takuya Yoda, Takao Yoda, Maiko Tanabe, Haruko Takeyama, Tsuyoshi Shirai |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
DNA Replication
0301 basic medicine Exonuclease DNA polymerase Archaeal Proteins DNA polymerase II DNA Mismatch Repair 01 natural sciences DNA polymerase delta Article 03 medical and health sciences Proliferating Cell Nuclear Antigen 0103 physical sciences Amino Acid Sequence DNA Polymerase beta Klenow fragment Multidisciplinary DNA clamp 010304 chemical physics biology Chemistry DNA Processivity Archaea Cell biology DNA-Binding Proteins 030104 developmental biology Multiprotein Complexes biology.protein PCNA complex |
| Zdroj: | Scientific Reports |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/srep44582 |
| Popis: | Family B DNA polymerases comprise polymerase and 3′ −>5′ exonuclease domains, and detect a mismatch in a newly synthesized strand to remove it in cooperation with Proliferating cell nuclear antigen (PCNA), which encircles the DNA to provide a molecular platform for efficient protein–protein and protein–DNA interactions during DNA replication and repair. Once the repair is completed, the enzyme must stop the exonucleolytic process and switch to the polymerase mode. However, the cue to stop the degradation is unclear. We constructed several PCNA mutants and found that the exonuclease reaction was enhanced in the mutants lacking the conserved basic patch, located on the inside surface of PCNA. These mutants may mimic the Pol/PCNA complex processing the mismatched DNA, in which PCNA cannot interact rigidly with the irregularly distributed phosphate groups outside the dsDNA. Indeed, the exonuclease reaction with the wild type PCNA was facilitated by mismatched DNA substrates. PCNA may suppress the exonuclease reaction after the removal of the mismatched nucleotide. PCNA seems to act as a “brake” that stops the exonuclease mode of the DNA polymerase after the removal of a mismatched nucleotide from the substrate DNA, for the prompt switch to the DNA polymerase mode. |
| Databáze: | OpenAIRE |
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