Two essential DNA polymerases at the bacterial replication fork
Résumé
DNA replication in bacteria is carried out by a multiprotein complex, which is thought to contain only one essential DNA polymerase, specified by the dnaE gene in Escherichia coli and the polC gene in Bacillus subtilis . Bacillus subtilis genome analysis has revealed another DNA polymerase gene, dnaE BS , which is homologous to dnaE . We show that, in B. subtilis , dnaE BS is essential for cell viability and for the elongation step of DNA replication, as is polC, and we conclude that there are two different essential DNA polymerases at the replication fork of B. subtilis , as was previously observed in eukaryotes. dnaE BS appears to be involved in the synthesis of the lagging DNA strand and to be associated with the replication factory, which suggests that two different polymerases carry out synthesis of the two DNA strands in B. subtilis and in many other bacteria that contain both polC and dnaE genes.
Domaines
Biologie cellulaireOrigine | Fichiers produits par l'(les) auteur(s) |
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