... interactions established in the active site is also of relevance The active site: structural and electrostatic basis of HtA function The reaction catalyzed by ribotoxins follows a mechanism of transphosphorylation, ... Pozo A & Gavilanes JG (2001) RNase U2 and alphasarcin: a study of relationships Meth Enzymol 341, 33 5–3 51 ´ Lacadena J, Alvarez-Garcı´ a E, Carreras-Sangra N, ´ Herrero-Galan E, Alegre-Cebollada ... Desolvation of the charged groups should affect their pKa values, increasing the pKa of carboxylates and decreasing the pKa of histidines [24] Structurally, the architecture of the active site in HtA is...