Concept explainers
If DnaA was not regulated in Escherichia coli and multiple rounds of replication were completed before cell division, what would be the consequence to the daughter cell and why? Would the resulting cell still be considered haploid?
To explain:
What would be the consequences if DnaA was not regulated during the replication of E.coli and why multiple rounds of replication occur before cell division? The resulting cell will be haploid, why?
Concept introduction:
DnaA is a key protein that triggers the initiation of bacterial replication. It also known as the replication initiation factor because this protein promotes the unwinding of DNA (deoxyribo nucleic acid) at the oriC site. The concentration of DnaA is responsible for the onset of DNA replication. These proteins are accumulated during the growth phase of bacteria.
Explanation of Solution
If DnaA was not regulated during the replication of E.coli, multiple rounds of replication might occur resulting in multiple copies of DNA. Multiple regulatory mechanisms are present in a bacteria to control DnaA protein. The oriC site of E.coli is rich in adenosine-thymine concentration (AT) and approximately ten DnaA binds with 9bp region of DNA, making it AT rich. Also eight DnaA binding regions are present within the oriC site. Therefore, if DnaA was not regulated properly during the replication process, it will be incomplete and an incomplete copy of the parental DNA might remain after replication and cell division thus making a haploid cell.
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Chapter 7 Solutions
Brock Biology of Microorganisms (15th Edition)
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