title: Contribution of anion-π interactions to the stability of Sm/LSm proteins.
abstract: We have analyzed the influence of anion-π interactions to the stability of Sm/LSm assemblies. The side chain of Glu is more likely to be in anion-π interactions than Asp. Phe has the highest occurrence in these interactions than the other two π residues. Among the anion-π residue pairs, Glu-Phe residue pair showed the maximum number of anion-π. We have found hot-spot residues forming anion-π interactions, and Glu-Phe is the most common hot-spot interacting pair. The significant numbers of anion-π interacting residues identified in the dataset were involved in the formation of multiple anion-π interactions. More than half of the residues involved in these interactions are evolutionarily conserved. The anion-π interaction energies are distance and orientation dependent. It was found that anion-π interactions showed energy less than -15 kcal mol(-1), and most of them have energy in the range -2 to -9 kcal mol(-1). Solvent accessibility pattern of Sm/LSm proteins reveals that all of the interacting residues are preferred to be in buried regions. Most of the interacting residues preferred to be in strand. A significant percentage of anion-π interacting residues are located as stabilization centers and thus might provide additional stability to these proteins. The simultaneous interaction of anions and cations on different faces of the same π-system has been observed. On the whole, the results presented in this work will be very useful for understanding the contribution of anion-π interaction to the stability of Sm/LSm proteins.
authors.affiliation: Faculty of Chemistry, University of Belgrade, Belgrade, Serbia.
authors.forename: Luka M
authors.initials: LM
authors.lastname: Breberina
authors.forename: Miloš K
authors.initials: MK
authors.lastname: Milčić
authors.forename: Milan R
authors.initials: MR
authors.lastname: Nikolić
authors.forename: Srđan Đ
authors.initials: SĐ
authors.lastname: Stojanović
mesh_terms: D003198:Computer Simulation; D055550:Protein Stability; D017433:Protein Structure, Secondary; D016601:RNA-Binding Proteins / Q000737:chemistry*; D017411:Ribonucleoproteins, Small Nuclear / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D016601:RNA-Binding Proteins; D017411:Ribonucleoproteins, Small Nuclear