| Autor: |
Marceau, Aimee H, Bahng, Soon, Massoni, Shawn C, George, Nicholas P, Sandler, Steven J, Marians, Kenneth J, Keck, James L |
| Jazyk: |
angličtina |
| Rok vydání: |
2011 |
| Předmět: |
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| Popis: |
Interactions between single-stranded DNA-binding proteins (SSBs) and the DNA replication machinery are found in all organisms, but the roles of these contacts remain poorly defined. In Escherichia coli, SSB's association with the χ subunit of the DNA polymerase III holoenzyme has been proposed to confer stability to the replisome and to aid delivery of primers to the lagging-strand DNA polymerase. Here, the SSB-binding site on χ is identified crystallographically and biochemical and cellular studies delineate the consequences of destabilizing the χ/SSB interface. An essential role for the χ/SSB interaction in lagging-strand primer utilization is not supported. However, sequence changes in χ that block complex formation with SSB lead to salt-dependent uncoupling of leading- and lagging-strand DNA synthesis and to a surprising obstruction of the leading-strand DNA polymerase in vitro, pointing to roles for the χ/SSB complex in replisome establishment and maintenance. Destabilization of the χ/SSB complex in vivo produces cells with temperature-dependent cell cycle defects that appear to arise from replisome instability. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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