RNA: Another level of gene control in prokaryotes Flashcards Preview

Molecular Genetics 4500 > RNA: Another level of gene control in prokaryotes > Flashcards

Flashcards in RNA: Another level of gene control in prokaryotes Deck (10):
1

RNA is....

Another level of gene control in prokaryotes

2

Gene regulation using RNA molecules in prokaryotes:

Antisense RNA control

Riboswitches

Riboswitches that can act as Ribozymes

3

antisense RNA

An RNA molecule (synthesized in vivo or in vitro) with a ribonucleotide sequence that is complementary to part of an mRNA molecule.

4

Osmolarity

Osmolarity conditions affects movement of water across a membrane due to differences in ion concentrations on inside and outside of membrane

5

____ proteins function as diffusion pores on ____ membrane

OmpF proteins function as diffusion pores on bacterial membrane

6

Lower OmpF protein....

less diffusion across membrane

7

Antisense RNA control under high osmolarity:

Lower OmpF protein; less diffusion across membrane

8

Riboswitch control of translation

A Regulatory Protein binds to the Riboswitch and Stabilizes a Secondary Structure that masks a Ribosome-Binding site.
-----> No translation takes place.

Without the regulatory protein, the riboswitch assumes an alternative secondary structure that makes the ribosome-binding site available
---->Translation takes place.

9

Riboswitch

Can be repressive (like the vitamin B12 example)

OR

the presence of the regulatory protein can cause a secondary structure that permits translation (inductive)

10

Riboswitches that act as Ribozymes

GlcN6P gene: catalyzes reaction to produce a sugar, glucosamine-6-phosphate from a precursor

However, if there is plenty of GlcN6P around, it binds to the ribozyme region, altering its structure, leading to the active form of the ribozyme, which degrades the mRNA (doesn’t make more enzyme when its not needed!)