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Cocrystal structure of a class I preQ1 riboswitch reveals a pseudoknot recognizing an essential hypermodified nucleobase.

ABSTRACT: Riboswitches are mRNA domains that bind metabolites and modulate gene expression in cis. We report cocrystal structures of a remarkably compact riboswitch (34 nucleotides suffice for ligand recognition) from Bacillus subtilis that is selective for the essential nucleobase preQ(1) (7-aminomethyl-7-deazaguanine). The structures reveal a previously unrecognized pseudoknot fold and suggest a conserved gene-regulatory mechanism whereby ligand binding promotes sequestration of an RNA segment that otherwise assembles into a transcriptional antiterminator.

SUBMITTER: Klein DJ

PROVIDER: S-EPMC2657927 | biostudies-literature | 2009 Mar

REPOSITORIES: biostudies-literature

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Cocrystal structure of a class I preQ1 riboswitch reveals a pseudoknot recognizing an essential hypermodified nucleobase.

Klein Daniel J DJ Edwards Thomas E TE Ferré-D'Amaré Adrian R AR

Nature structural & molecular biology 20090222 3

Riboswitches are mRNA domains that bind metabolites and modulate gene expression in cis. We report cocrystal structures of a remarkably compact riboswitch (34 nucleotides suffice for ligand recognition) from Bacillus subtilis that is selective for the essential nucleobase preQ(1) (7-aminomethyl-7-deazaguanine). The structures reveal a previously unrecognized pseudoknot fold and suggest a conserved gene-regulatory mechanism whereby ligand binding promotes sequestration of an RNA segment that othe ...[more]

PMID: 19234468

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