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Tuning the replication fork progression by the initiation frequency
Author(s) -
González Moreno Sara,
Mata Martín Carmen,
Ferrera Guillén Encarna,
Guzmán Elena C.
Publication year - 2013
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.12127
Subject(s) - biology , ribonucleotide reductase , genetics , dna replication , mutant , cell division , cell cycle , chromosome , replication (statistics) , allele , mutation , dna synthesis , cell , microbiology and biotechnology , dna , gene , virology , protein subunit
Summary The thermo‐resistant period of the thermo‐sensitive ribonucleotide reductase RNR 101 encoded by the nrdA101 allele in E scherichia coli is prolonged for 50 min at 42°C, enabling an increase in DNA content of about 45%. Assuming that fork progression in the nrdA101 mutant is impaired, the question whether reduced number of ongoing replication rounds altered the thermo‐resistant period in this strain was investigated. Decreases in the oriC / terC ratio and in the number of oriC per cell at 30°C were found in the presence of oriC228 , oriC229 and oriC239 alleles in strain nrdA101 . Correlated with this effect, increased thermo‐resistance period of the RNR 101 was allowed, and the detrimental effects on cell division, chromosome segregation and cell viability observed in the nrdA101 mutant at 42°C were suppressed. These results indicate that conditions leading to chromosome initiation deficiency at 30°C enhance the replication fork progression in the nrdA101 mutant at 42°C. We propose that coordination between initiation frequency and replication fork progression could be significant for most of the replication systems with important consequences in their cell cycle regulation.