Molecular Mechanism of Heat Shock-Provoked Disassembly of the Coliphage λ Replication Complex
| Autor: | Anna Herman-Antosiewicz, Grzegorz Węgrzyn, Alicja Węgrzyn, Karol Taylor |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
DNA Replication
Transcription Genetic Genetics and Molecular Biology Biology Virus Replication Microbiology Viral Proteins chemistry.chemical_compound Plasmid Chaperonin 10 Escherichia coli Viral Regulatory and Accessory Proteins Heat shock Molecular Biology Adenosine Triphosphatases Models Genetic DNA Superhelical Escherichia coli Proteins Serine Endopeptidases DNA replication Chaperonin 60 Endopeptidase Clp GroES Bacteriophage lambda Molecular biology GroEL DNA-Binding Proteins Repressor Proteins DNA Topoisomerases Type II chemistry Biophysics ATPases Associated with Diverse Cellular Activities DNA supercoil HSP60 Heat-Shock Response DNA Molecular Chaperones Plasmids |
| Zdroj: | Journal of Bacteriology. 180:2475-2483 |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/jb.180.9.2475-2483.1998 |
| Popis: | We have found previously that, in contrast to the free O initiator protein of λ phage or plasmid rapidly degraded by the Escherichia coli ClpP/ClpX protease, the λO present in the replication complex (RC) is protected from proteolysis. However, in cells growing in a complete medium, a temperature shift from 30 to 43°C resulted in the decay of the λO fraction, which indicated disassembly of RC. This process occurred due to heat shock induction of the groE operon, coding for molecular chaperones of the Hsp60 system. Here we demonstrate that an increase in the cellular concentration of GroEL and GroES proteins is not in itself sufficient to cause RC disassembly. Another requirement is a DNA gyrase-mediated negative resupercoiling of λ plasmid DNA, which counteracts DNA relaxation and starts to dominate 10 min after the temperature upshift. We presume that RC dissociates from λ DNA during the negative resupercoiling, becoming susceptible to the subsequent action of GroEL/S and ClpP/ClpX proteins. In contrast to λ cro + , in λ cro − plasmid-harboring cells, the RC reveals heat shock resistance. After temperature upshift of the λ cro ts plasmid-harboring cells, a Cro repressor-independent control of λ DNA replication and heat shock resistance of RC are established before the period of DNA gyrase-mediated negative supercoiling. We suggest that the tight binding of RC to λ DNA is due to interaction of RC with other DNA-bound proteins, and is related to the molecular basis of the λ cro − plasmid replication control. |
| Databáze: | OpenAIRE |
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