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that they carn Some bacteriophages are temperate, meaning initiate lytic events

ID: 209635 • Letter: T

Question

that they carn Some bacteriophages are temperate, meaning initiate lytic events or integrate into the host genome as a prophage. Integration initiates a state called lysogeny in which the virus does not destroy the cell. A well-studied lysogenic virus of Escherichia coli is phage lambda; this phage uses an intricate regulatory system to govern whether the lytic or lysogenic state is initiated following infection. Q What enzyme is required to form a prophage, and what are the two main transcriptional repressors that control whether lambda proceeds to lysogeny or lysis?

Explanation / Answer

integrated phage DNA or prophage is formed with the help of enzyme integrase. phage DNA integrates with bacterial chromosome with the help of enzyme integrase. continued division then makes many cells with prophage.

CI and cro proteins are the two main transcriptional repressors that control whether lamba proceeds to lysogeny or lysis. at lower concentration CI proteins are found to repress major rightward and leftward transcription and an activator of transcription for maintainence of repressor. whereas, cro proteins at lower concentration is found to be repressor of transcription for repressor maintainence and at higher concentration it also deactivate the major rightward and leftward transcription.