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Ribonucleotide reductase and the regulation of DNA replication: an old story and an ancient heritage
Author(s) -
Herrick John,
Sclavi Bianca
Publication year - 2007
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2006.05493.x
Subject(s) - ribonucleotide reductase , biology , dnaa , dna replication , dna synthesis , eukaryotic dna replication , origin recognition complex , dna , pre replication complex , circular bacterial chromosome , control of chromosome duplication , replication factor c , cell cycle , biochemistry , microbiology and biotechnology , cell , gene , protein subunit
Summary All organisms that synthesize their own DNA have evolved mechanisms for maintaining a constant DNA/cell mass ratio independent of growth rate. The DNA/cell mass ratio is a central parameter in the processes controlling the cell cycle. The co‐ordination of DNA replication with cell growth involves multiple levels of regulation. DNA synthesis is initiated at specific sites on the chromosome termed origins of replication, and proceeds bidirectionally to elongate and duplicate the chromosome. These two processes, initiation and elongation, therefore determine the total rate of DNA synthesis in the cell. In Escherichia coli , initiation depends on the DnaA protein while elongation depends on a multiprotein replication factory that incorporates deoxyribonucleotides (dNTPs) into the growing DNA chain. The enzyme ribonucleotide reductase (RNR) is universally responsible for synthesizing the necessary dNTPs. In this review we examine the role RNR plays in regulating the total rate of DNA synthesis in E. coli and, hence, in maintaining constant DNA/cell mass ratios during normal growth and under conditions of DNA stress.