Chapter 22 Riboswitches and RNA sensors

riboswitches are sequence elements typically located in

5’UTR of genes

what do riboswitches do

affect transcription or translation

three riboswitch sequence elements

aptamer domain, translation platform, switching sequence

what does aptamer domain do

binds ligand/metabolite

what does translation platform do

transduces metabolite binding event in change in gene expression

what does switching sequence do

flexible and can change conformation upon binding, linked to aptamer and translation platform

in repression, ligand-binding favors formation of a

terminator

activation functions to

repress formation of a terminator

alternative function of riboswitch

direct cleavage of nascent mRNA

Type I riboswitch

ligand-dependent changes in the RNA secondary structure are limited to regions located closer to BS

Type II riboswitches

contain bipartite ligand binding pockets, upon binding, two binding sites are brough and held together