Idiosyncratically tuned switching behavior of riboswitch aptamer domains revealed by comparative small-angle X-ray scattering analysis

Journal Article · Tue May 25 04:00:00 EDT 2010 · RNA

DOI:https://doi.org/10.1261/rna.1852310· OSTI ID:1002390

Baird, Nathan J; Ferré-D'Amaré, Adrian R ^[1]

---

1. HHMI

Riboswitches are structured mRNA elements that regulate gene expression upon binding specific cellular metabolites. It is thought that the highly conserved metabolite-binding domains of riboswitches undergo conformational change upon binding their cognate ligands. To investigate the generality of such a mechanism, we employed small-angle X-ray scattering (SAXS). We probed the nature of the global metabolite-induced response of the metabolite-binding domains of four different riboswitches that bind, respectively, thiamine pyrophosphate (TPP), flavin mononucleotide (FMN), lysine, and S-adenosyl methionine (SAM). We find that each RNA is unique in its global structural response to metabolite. Whereas some RNAs exhibit distinct free and bound conformations, others are globally insensitive to the presence of metabolite. Thus, a global conformational change of the metabolite-binding domain is not a requirement for riboswitch function. It is possible that the range of behaviors observed by SAXS, rather than being a biophysical idiosyncrasy, reflects adaptation of riboswitches to the regulatory requirements of their individual genomic context.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: USDOE
• OSTI ID: 1002390
• Journal Information: RNA, Journal Name: RNA Journal Issue: 03, 2010 Vol. 16
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
99 GENERAL AND MISCELLANEOUS
CONFORMATIONAL CHANGES
GENES
ISOALLOXAZINES
LYSINE
METABOLITES
METHIONINE
PYROPHOSPHATES
RNA
SCATTERING
THIAMINE