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bioRxiv · 10.1101/354654

Modeling of DNA replication in rapidly growing bacteria with one and two replication origins

Retkute, R.·Hawkins, M.·Rudolph, C. J.·Nieduszynsk, C. A.
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Abstract

In rapidly growing bacteria initiation of DNA replication occurs at intervals shorter than the time required for completing genome duplication, leading to overlapping rounds of replication. We propose a mathematical model of DNA replication defined by the periodicity of replication initiation. Our model predicts that a steeper gradient of the replication profile is to be expected in origin proximal regions due to the overlapping rounds of synthesis. By comparing our model with experimental data from a strain with an additional replication origin, we predict defined alterations to replication parameters: (i) a reduced fork velocity when there were twice as many forks as normal; (ii) a slower fork speed if forks move in a direction opposite to normal, in line with head-on replication-transcription collisions being a major obstacle for fork progression; (iii) slower cell doubling for a double origin strain compared to wild-type cells; and (iv) potentially an earlier initiation of replication at the ectopic origin than at the natural origin, which, however, does not a{dot}ect the overall time required to complete synthesis.

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Retkute, R., Hawkins, M., Rudolph, C. J., Nieduszynsk, C. A.. 2018-06-24. Modeling of DNA replication in rapidly growing bacteria with one and two replication origins. https://doi.org/10.1101/354654

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