Structural Characterization of the Cotranscriptional Folding of the Thiamin Pyrophosphate Sensing thiC Riboswitch in Escherichia coli.
Biochemistry
; 63(13): 1608-1620, 2024 Jul 02.
Article
em En
| MEDLINE
| ID: mdl-38864595
ABSTRACT
Riboswitches are RNA-regulating elements that mostly rely on structural changes to modulate gene expression at various levels. Recent studies have revealed that riboswitches may control several regulatory mechanisms cotranscriptionally, i.e., during the transcription elongation of the riboswitch or early in the coding region of the regulated gene. Here, we study the structure of the nascent thiamin pyrophosphate (TPP)-sensing thiC riboswitch in Escherichia coli by using biochemical and enzymatic conventional probing approaches. Our chemical (in-line and lead probing) and enzymatic (nucleases S1, A, T1, and RNase H) probing data provide a comprehensive model of how TPP binding modulates the structure of the thiC riboswitch. Furthermore, by using transcriptional roadblocks along the riboswitch sequence, we find that a certain portion of nascent RNA is needed to sense TPP that coincides with the formation of the P5 stem loop. Together, our data suggest that conventional techniques may readily be used to study cotranscriptional folding of nascent RNAs.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Tiamina Pirofosfato
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Escherichia coli
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Riboswitch
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Dobramento de RNA
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Conformação de Ácido Nucleico
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article