Biomaterial Database

Structure of the eukaryotic thiamine pyrophosphate riboswitch with its regulatory ligand. 2006

Stéphane Thore, and Marc Leibundgut, and Nenad Ban

ETH Zurich, Institute of Molecular Biology and Biophysics, 8092 Zurich, Switzerland. ban@mol.biol.ethz.ch

Riboswitches are untranslated regions of messenger RNA, which adopt alternate structures depending on the binding of specific metabolites. Such conformational switching regulates the expression of proteins involved in the biosynthesis of riboswitch substrates. Here, we present the 2.9 angstrom-resolution crystal structure of the eukaryotic Arabidopsis thaliana thiamine pyrophosphate (TPP)-specific riboswitch in complex with its natural ligand. The riboswitch specifically recognizes the TPP via conserved residues located within two highly distorted parallel "sensor" helices. The structure provides the basis for understanding the reorganization of the riboswitch fold upon TPP binding and explains the mechanism of resistance to the antibiotic pyrithiamine.

UI	MeSH Term	Description	Entries
D008024	Ligands	A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)	Ligand
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D008958	Models, Molecular	Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.	Molecular Models,Model, Molecular,Molecular Model
D009690	Nucleic Acid Conformation	The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.	DNA Conformation,RNA Conformation,Conformation, DNA,Conformation, Nucleic Acid,Conformation, RNA,Conformations, DNA,Conformations, Nucleic Acid,Conformations, RNA,DNA Conformations,Nucleic Acid Conformations,RNA Conformations
D011745	Pyrithiamine	A thiamine antagonist due to its inhibition of thiamine pyrophosphorylation. It is used to produce thiamine deficiency.	Heterovitamin B 1,Neopyrithiamine,1, Heterovitamin B,B 1, Heterovitamin
D003460	Crystallization	The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Crystalline Polymorphs,Polymorphism, Crystallization,Crystal Growth,Polymorphic Crystals,Crystal, Polymorphic,Crystalline Polymorph,Crystallization Polymorphism,Crystallization Polymorphisms,Crystals, Polymorphic,Growth, Crystal,Polymorph, Crystalline,Polymorphic Crystal,Polymorphisms, Crystallization,Polymorphs, Crystalline
D004351	Drug Resistance	Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.	Resistance, Drug
D006860	Hydrogen Bonding	A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.	Hydrogen Bonds,Bond, Hydrogen,Hydrogen Bond
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining