C-terminal extension of the yeast mitochondrial DNA polymerase determines the balance between synthesis and degradation.
Saccharomyces cerevisiae mitochondrial DNA polymerase (Mip1) contains a C-terminal extension (CTE) of 279 amino acid residues. The CTE is required for mitochondrial DNA maintenance in yeast but is absent in higher eukaryotes. Here we use recombinant Mip1 C-terminal deletion mutants to investigate fu...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2012-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3303844?pdf=render |
| _version_ | 1819045063065337856 |
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| author | Katrin Viikov Olga Jasnovidova Tiina Tamm Juhan Sedman |
| author_facet | Katrin Viikov Olga Jasnovidova Tiina Tamm Juhan Sedman |
| author_sort | Katrin Viikov |
| collection | DOAJ |
| description | Saccharomyces cerevisiae mitochondrial DNA polymerase (Mip1) contains a C-terminal extension (CTE) of 279 amino acid residues. The CTE is required for mitochondrial DNA maintenance in yeast but is absent in higher eukaryotes. Here we use recombinant Mip1 C-terminal deletion mutants to investigate functional importance of the CTE. We show that partial removal of the CTE in Mip1Δ216 results in strong preference for exonucleolytic degradation rather than DNA polymerization. This disbalance in exonuclease and polymerase activities is prominent at suboptimal dNTP concentrations and in the absence of correctly pairing nucleotide. Mip1Δ216 also displays reduced ability to synthesize DNA through double-stranded regions. Full removal of the CTE in Mip1Δ279 results in complete loss of Mip1 polymerase activity, however the mutant retains its exonuclease activity. These results allow us to propose that CTE functions as a part of Mip1 polymerase domain that stabilizes the substrate primer end at the polymerase active site, and is therefore required for efficient mitochondrial DNA replication in vivo. |
| first_indexed | 2024-12-21T10:22:37Z |
| format | Article |
| id | doaj.art-8da09f5bbde742f89630b5a60c7b6030 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-21T10:22:37Z |
| publishDate | 2012-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-8da09f5bbde742f89630b5a60c7b60302022-12-21T19:07:23ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-0173e3348210.1371/journal.pone.0033482C-terminal extension of the yeast mitochondrial DNA polymerase determines the balance between synthesis and degradation.Katrin ViikovOlga JasnovidovaTiina TammJuhan SedmanSaccharomyces cerevisiae mitochondrial DNA polymerase (Mip1) contains a C-terminal extension (CTE) of 279 amino acid residues. The CTE is required for mitochondrial DNA maintenance in yeast but is absent in higher eukaryotes. Here we use recombinant Mip1 C-terminal deletion mutants to investigate functional importance of the CTE. We show that partial removal of the CTE in Mip1Δ216 results in strong preference for exonucleolytic degradation rather than DNA polymerization. This disbalance in exonuclease and polymerase activities is prominent at suboptimal dNTP concentrations and in the absence of correctly pairing nucleotide. Mip1Δ216 also displays reduced ability to synthesize DNA through double-stranded regions. Full removal of the CTE in Mip1Δ279 results in complete loss of Mip1 polymerase activity, however the mutant retains its exonuclease activity. These results allow us to propose that CTE functions as a part of Mip1 polymerase domain that stabilizes the substrate primer end at the polymerase active site, and is therefore required for efficient mitochondrial DNA replication in vivo.http://europepmc.org/articles/PMC3303844?pdf=render |
| spellingShingle | Katrin Viikov Olga Jasnovidova Tiina Tamm Juhan Sedman C-terminal extension of the yeast mitochondrial DNA polymerase determines the balance between synthesis and degradation. PLoS ONE |
| title | C-terminal extension of the yeast mitochondrial DNA polymerase determines the balance between synthesis and degradation. |
| title_full | C-terminal extension of the yeast mitochondrial DNA polymerase determines the balance between synthesis and degradation. |
| title_fullStr | C-terminal extension of the yeast mitochondrial DNA polymerase determines the balance between synthesis and degradation. |
| title_full_unstemmed | C-terminal extension of the yeast mitochondrial DNA polymerase determines the balance between synthesis and degradation. |
| title_short | C-terminal extension of the yeast mitochondrial DNA polymerase determines the balance between synthesis and degradation. |
| title_sort | c terminal extension of the yeast mitochondrial dna polymerase determines the balance between synthesis and degradation |
| url | http://europepmc.org/articles/PMC3303844?pdf=render |
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