Bacterial cells must regulate chromosome replication such that the chromosome is
ID: 204913 • Letter: B
Question
Bacterial cells must regulate chromosome replication such that the chromosome is completely replicated prior to cell division but also so that the cell does not make too many copies of the chromosome. DnaA facilitates replication when bound to DNA in the origin of replication in E. coli. Which of the following is NOT a form of regulation that inhibits initiation of another round of replication once the replication forks have been formed?
Bacterial cells must regulate chromosome replication such that the chromosome is completely replicated prior to cell division but also so that the cell does not make too many copies of the chromosome. DnaA facilitates replication when bound to DNA in the origin of replication in E. coli. Which of the following is NOT a form of regulation that inhibits initiation of another round of replication once the replication forks have been formed?
binding of ATP to DnaA, forming DnaA-ATP binding of the SeqA protein to GATC sequences in the oriC region, blocking DnaA binding binding of SeqA proteins to the GATC sequence in the dnaA promoter, causing repression hemimethylation of adenine residues in the GATC sequences on the chromosomeExplanation / Answer
Option 1st is the correct answer. Binding of ATP to DnaA activates DnaA. Active form of DnaA binds to oriC region and initiates replication and thus binding of DnaA does not inhibit another round of replication rather it promotes initiation of replication. Just after cell division the level of active form of DnaA becomes lower and it rises with the progress of cell cycle by binding with ATP. Hence it is not a regulation that inhibits initiation of another round of replication once the replication forks have been formed.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.