title: A Non-Invasive NMR Method Based on Histidine Imidazoles to Analyze the pH-Modulation of Protein-Nucleic Acid Interfaces.
abstract: A useful (2) J(N-H) coupling-based NMR spectroscopic approach is proposed to unveil, at the molecular level, the contribution of the imidazole groups of histidines from RNA/DNA-binding proteins on the modulation of binding to nucleic acids by pH. Such protonation/deprotonation events have been monitored on the single His96 located at the second RNA/DNA recognition motif (RRM2) of T-cell intracellular antigen-1 (TIA-1) protein. The pKa values of the His96 ionizable groups were substantially higher in the complexes with short U-rich RNA and T-rich DNA oligonucleotides than those of the isolated TIA-1 RRM2. Herein, the methodology applied to determine changes in pKa of histidine side chains upon DNA/RNA binding, gives valuable information to understand the pH effect on multidomain DNA/RNA-binding proteins that shuttle among different cellular compartments.
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis cicCartuja, Universidad de Sevilla - CSIC, Avenida Américo Vespucio 49, 41092 Sevilla (Spain).
authors.forename: Isabel
authors.initials: I
authors.lastname: Cruz-Gallardo
authors.forename: Rebecca
authors.initials: R
authors.lastname: Del Conte
authors.forename: Adrián
authors.initials: A
authors.lastname: Velázquez-Campoy
authors.forename: Sofía M
authors.initials: SM
authors.lastname: García-Mauriño
authors.forename: Irene
authors.initials: I
authors.lastname: Díaz-Moreno
mesh_terms: D004268:DNA-Binding Proteins / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D009696:Nucleic Acids / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D012313:RNA / Q000737:chemistry*
chemical_list: D004268:DNA-Binding Proteins; D009696:Nucleic Acids; D006639:Histidine; D012313:RNA
keywords: DNA; NMR spectroscopy; histidine; nucleic acids; proteins