Related Experiment Video
Updated: Jun 12, 2026

Sedimentation Equilibrium of a Small Oligomer-forming Membrane Protein: Effect of Histidine Protonation on Pentameric Stability
Published on: April 2, 2015
Nucleotide-amino acid interactions in the L-His-IMP.MeOH.H(2)O complex
Katarzyna Rlepokura1, Rafał Petrus
1Faculty of Chemistry, University of Wrocław, 14 Joliot-Curie Street, 50-383 Wrocław, Poland. slep@eto.wchuwr.pl
Abstract:
In the crystal structure of the methanol-solvated monohydrated complex of L-histidine (His) with inosine 5'-monophosphate (IMP), namely L-histidinium inosine-5'-phosphate methanol solvate monohydrate, C(6)H(10)N(3)O(2)(+).C(10)H(12)N(4)O(8)P(-).CH(3)OH.H(2)O, most of the interactions between IMP anions (anti/C3'-endo/gauche-gauche conformers) are realized between the riboses and hypoxanthine bases in a trans sugar-edge/sugar-edge geometry, and between the phosphate groups. The base Watson-Crick edge is involved in additional methanol-mediated IMP...MeOH...IMP contacts. Specific and nonspecific nucleotide-amino acid (IMP...His) interactions engage the Hoogsteen edges of the base and phosphate group, respectively. Additional stabilization of His...IMP contacts is provided by pi-pi stacking between the imidazolium ring of His and the hypoxanthine base of IMP. The results may indicate the possible recognition mechanism between His and IMP.
Related Concept Videos
Amino acids
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Formation of Complex Ions
Noncovalent Attractions in Biomolecules
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Noncovalent Attractions in Biomolecules
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Nucleic Acid Structure
DNA Structure
DNA has a double-helix structure. The...

