L15: Regulatory RNAs (Prokaryotes)

Question 1

what are sRNAs

Answer 1

• a class of bacterial regulatory RNAs 80-110 nucleotides in size
• bind to target RNA transcripts

Question 2

sRNAs - what can they result in?

Answer 2

• Destruction
• Prevention of Translation
• Stimulation of Translation

Question 3

sRNAs - destruction

Answer 3

• sRNAs recognizes and binds to target mRNA due to complementarity base pairing
• it then creates a double-stranded region that is recognized by RNaseE
• the target mRNA is then degraded

Question 4

sRNAs - prevention of translation

Answer 4

binds and occludes (obstructs) ribosome binding site (RBS)

Question 5

sRNAs - stimulation of translation

Answer 5

sRNA binding unmasks a hidden RBS

Question 6

what are riboswitches?

Answer 6

• they are found in the 5’ untranslated region (5’ UTR) of the gene they regulate
• they can regulate gene expression at the level of translation or transcription