THE MOLECULAR BASIS OF INHERITANCE
DNA REPLICATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Replication will occur via RNA polymerase alone.
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The DNA will supercoil.
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No replication fork will be formed.
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No proofreading will occur.
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Detailed explanation-1: -In E. coli, there is a mutation in a gene called dnaB that alters the helicase that normally acts at the origin of replication. Which of the following events would you expect to occur as a result of this mutation? No replication fork will be formed.
Detailed explanation-2: -In Escherichia coli, the DnaB helicase forms the basis for the assembly of the DNA replication complex. The stability of DnaB at the replication fork is likely important for successful replication initiation and progression.
Detailed explanation-3: -Genetic and biochemical analyses indicate that the Escherichia coli dnaB replication protein functions in the propagation of replication forks in the bacterial chromosome. We have found that the dnaB protein is a DNA helicase that is capable of unwinding extensive stretches of double-stranded DNA.
Detailed explanation-4: -The E. coli DnaB helicase is a hexameric protein comprised of six 52 kDa monomers (3–6). DnaB is a multifunctional enzyme that controls the formation and translocation of the replisome in E. coli and phage DNA replication.
Detailed explanation-5: -Initiating new rounds of Escherichia coli chromosome replication requires DnaA-ATP to unwind the replication origin, oriC, and load DNA helicase.