2hol
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Crystal structure of an E. coli thi-box riboswitch bound to thiamine pyrophosphate, barium ions
OverviewOverview
Riboswitches are noncoding mRNA elements that bind small-molecule, metabolites with high affinity and specificity, and they regulate the, expression of associated genes. The thi-box riboswitch can exhibit a, 1000-fold higher affinity for thiamine pyrophosphate over closely related, noncognate compounds such as thiamine monophosphate. To understand the, chemical basis of thi-box pyrophosphate specificity, we have determined, crystal structures of an E. coli thi-box bound to thiamine pyrophosphate, thiamine monophosphate, and the structural analogs benfotiamine and, pyrithiamine. When bound to monophosphorylated compounds, the RNA elements, that recognize the thiamine and phosphate moieties of the ligand move, closer together. This allows the riboswitch to recognize the monophosphate, in a manner similar to how it recognizes the beta-phosphate of thiamine, pyrophosphate. In the pyrithiamine complex, the pyrophosphate binding site, is largely unstructured. These results show how the riboswitch can bind to, various metabolites, and why the thi-box preferentially binds thiamine, pyrophosphate.
About this StructureAbout this Structure
2HOL is a Protein complex structure of sequences from [1] with , , and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of the thi-box riboswitch bound to thiamine pyrophosphate analogs reveal adaptive RNA-small molecule recognition., Edwards TE, Ferre-D'Amare AR, Structure. 2006 Sep;14(9):1459-68. PMID:16962976
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