Bacterial Regulation Flashcards
Give some examples of post-transcriptional regulation.
Riboswitches.
Attenuation
Regulation of aminoacyl tRNA synthethases
Give some examples of transcriptional regulation.
Binding of repressors or activators.
Attenuation.
Two-component systems
What is an antisense RNA? Is it transcriptional, post-transcriptional or post-translational?
A small RNA that base pairs complementary to mRNA and performs some kind of regulation. It is post-transcriptional.
Give some examples on how antisense RNAs can perform post-transcriptional regulation.
Inhibition of translation: antisense RNA can sit on the RBS and inhibit translation.
Activation of translation: The default structure of mRNA inhibits translation. Binding of antisense RNA can yield a structure that permits the ribosome to bind.
Degradation via translation block: antisense RNA sequesters the RBS, causing the mRNA to be degraded when not translated.
Degradation only: the sRNA can form a complex with RNaseE and Hfq, which may cleave the mRNA even if translation is initiated.
How does regulation via protein sequestration of CsrA work?
CsrA = protein regulating translation by binding mRNA. Can also bind to the stem loops in CsrB
CsrB = a sRNA consisting of 18 stem loops, each one can bind a CsrA protein.
When CsrA binds to CsrB instead of the target mRNA, the target mRNA is not regulated.
How can sRNAs work as storages for sigma70 factor?
The sRNA can mimic the open DNA-RNA Pol complex at the promoter –> inducing the sigma70 factor to bind and start transcription. When NTPs are low, the sigma factor just sits there without transcription.
How can sRNAs repress the further production of membrane proteins in case of misfolded proteins and membrane stress?
