30 Questions
What is the function of the σ factor in prokaryotic RNA polymerase?
To facilitate DNA recognition and RNA synthesis
What is the role of the up element in bacterial promoter structure?
To enhance binding of RNA polymerase to the promoter region
What is the mechanism of action of 6S RNA in regulating RNA polymerase activity?
By forming a 1:1 complex with RNA polymerase holoenzyme
What is the function of anti-σ factors in prokaryotic RNA polymerase?
To inhibit σ factor activity
What is the mechanism of action of MerR-type activators?
By interacting with domain 4 of the σ subunit
What is the mechanism of repression by steric hindrance?
By blocking recognition of the promoter by RNA polymerase holoenzyme
What is the function of AsiA protein in phage T4?
To redirect RNA polymerase holoenzyme to phage genes
What is the role of the discriminator element in bacterial promoter structure?
To recognize promoter elements
What is the function of SoxS in E. coli?
To target RNA polymerase holoenzyme to promoters with upstream Sox-box sequences
What is the mechanism of action of appropriators in phage T4?
By redirecting RNA polymerase holoenzyme to phage genes
What is the primary function of the σ54 family of sigma factors?
To require activation by a class of ATP-dependent activators
What is the role of the σ subunit in prokaryotic RNA polymerase?
To facilitate DNA recognition and promoter binding
How do phages regulate RNA polymerase activity?
By inducing conformational changes to block σ70's access to template DNA
What is the effect of 6S RNA on RNA polymerase activity?
It decreases the number of RNA polymerase molecules
What is the role of the α CTD subunit in prokaryotic RNA polymerase?
To bind to the up element of bacterial promoters
What is the mechanism of action of Class I activators?
They bind upstream of the promoter and make direct interaction with α CTD
What is the role of the extended -10 element in bacterial promoter structure?
It is essential for the formation of open complexes
What is the effect of anti-σ factors on σ factor activity?
They stabilize the σ factor and make it incompatible with RNA polymerase
What is the role of the discriminator element in bacterial promoter structure?
It is involved in the recognition of promoter elements by RNA polymerase
What is the mechanism of action of MerR-type activators?
They realign the -10 element and -35 element to allow RNA polymerase binding
What is the function of the σ70 family of sigma factors in prokaryotic RNA polymerase?
Housekeeping sigma factors that do not require activation
What is the effect of AsiA protein on RNA polymerase activity in phage T4?
It inhibits the activity of host RNA polymerase to favour phage gene transcription
What is the mechanism of action of repression by DNA looping?
Repressor binds to a distal site and loops back to the promoter to block RNA polymerase binding
What is the function of 6S RNA in regulating RNA polymerase activity?
It inhibits RNA polymerase activity by binding to the holoenzyme
What is the function of Class II repressors in prokaryotic RNA polymerase?
They bind downstream of the promoter and interact with the σ subunit
What is the function of the α NTD subunit in prokaryotic RNA polymerase?
It binds to the up element of DNA
What is the mechanism of action of appropriators in phage regulation?
They redirect the host RNA polymerase to transcribe phage genes
What is the function of the σ subunit in prokaryotic RNA polymerase?
It facilitates DNA recognition and promoter binding
What is the mechanism of action of anti-repression?
Binding of a secondary activator to counteract the inhibitory effects of a repressor
What is the function of the core enzyme in prokaryotic RNA polymerase?
It catalyses RNA synthesis but not promoter recognition
Test your knowledge of transcription units, operons, and RNA polymerase in prokaryotes. Learn about the core enzyme and holoenzyme, and how they interact with promoters and DNA. Assess your understanding of gene expression and regulation.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
