Revised model for the DNA replication fork in Bacillus subtilis: polymerase asymmetry

Paschalis, Vasileios (2017) Revised model for the DNA replication fork in Bacillus subtilis: polymerase asymmetry. PhD thesis, University of Nottingham.

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Replication of DNA is a vital process for growth and cell division in all domains of life. The mechanisms of helicase loading as well as hand-off of nascent RNA primers from the primase to the replicative polymerases during DNA synthesis are of fundamental importance. The prototype structural/functional model provided by the widely studied Gram-negative Escherichia coli DNA replication system is not universally applicable. The current model for the Gram-positive Bacillus subtilis DNA replication suggests that PolC is the main processive replicative polymerase with DnaE playing an essential but minor role during DNA synthesis. Our results suggest that DnaE is a major polymerase important for DNA replication and DNA repair. DnaE polymerase activity is stimulated in the presence of SSB, the clamp DnaN and PolC polymerase, its error-prone synthesis is modulated by the aforementioned proteins and its errors are corrected in trans by the PolC exonuclease domain, in a template specific ternary DNA-DnaE-PolC complex. Hereby, we propose a new revised model for DNA replication in Bacillus subtilis, where DnaE is the major replicative polymerase on the lagging strand and PolC, which is the major polymerase on the leading strand, provides the crucial proof-reading activity in trans. These findings revise the current model in Bacillus subtilis and suggest a division of labour between DnaE and PolC polymerases.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Soultanas, Panos
Oldham, N.
Subjects: Q Science > QD Chemistry > QD241 Organic chemistry
Q Science > QP Physiology > QP501 Animal biochemistry
Faculties/Schools: UK Campuses > Faculty of Science > School of Chemistry
Item ID: 40887
Depositing User: Paschalis, Vasileios
Date Deposited: 24 May 2017 13:08
Last Modified: 07 May 2020 12:16

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