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

Nat Struct Mol Biol. 2009 Mar;16(3):343-4. doi: 10.1038/nsmb.1563. Epub 2009 Feb 22.

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus subtilis / chemistry*
  • Bacillus subtilis / metabolism
  • Crystallography, X-Ray
  • Models, Molecular
  • Nucleic Acid Conformation*
  • Nucleoside Q / analogs & derivatives*
  • Nucleoside Q / metabolism
  • RNA, Bacterial / chemistry*
  • RNA, Bacterial / metabolism*
  • RNA, Messenger / chemistry*
  • RNA, Messenger / metabolism*

Substances

  • RNA, Bacterial
  • RNA, Messenger
  • Nucleoside Q
  • 7-aminomethyl-7-deazaguanosine

Associated data

  • PDB/3FU2
  • PDB/3FU4