A bacterial riboswitch class for the thiamin precursor HMP-PP employs a terminator-embedded aptamer.
Elife
; 82019 04 05.
Article
em En
| MEDLINE
| ID: mdl-30950790
ABSTRACT
We recently implemented a bioinformatics pipeline that can uncover novel, but rare, riboswitch candidates as well as other noncoding RNA structures in bacteria. A prominent candidate revealed by our initial search efforts was called the 'thiS motif' because of its frequent association with a gene coding for the ThiS protein, which delivers sulfur to form the thiazole moiety of the thiamin precursor HET-P. In the current report, we describe biochemical and genetic data demonstrating that thiS motif RNAs function as sensors of the thiamin precursor HMP-PP, which is fused with HET-P ultimately to form the final active coenzyme thiamin pyrophosphate (TPP). HMP-PP riboswitches exhibit a distinctive architecture wherein an unusually small ligand-sensing aptamer is almost entirely embedded within an otherwise classic intrinsic transcription terminator stem. This arrangement yields remarkably compact genetic switches that bacteria use to tune the levels of thiamin precursors during the biosynthesis of this universally distributed coenzyme.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tiamina
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Bacillus subtilis
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Regulação Bacteriana da Expressão Gênica
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Aptâmeros de Nucleotídeos
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Riboswitch
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article