Fig. 5: Summary of eukaryotic EndoU activation and structure comparison with homologs.
From: Molecular basis for the calcium-dependent activation of the ribonuclease EndoU
A Schematic representation of eukaryotic EndoU activation upon calcium and substrate binding. B A representative model of calcium-activated, RNA-bound hEndoU is shown alongside the crystal structure of apo-XendoU bound to a phosphate ion (PDB: 2C1W), the cryo-EM structure of SARS-CoV-2 Nsp15 NendoU in complex with dsRNA (PDB: 7TJ2), and the liquid-state structure of ribonuclease A in complex with uridine vanadate (PDB: 6RSA). For each model or structure, the catalytic histidines are highlighted (yellow). For the crystal structure of apo-XendoU, the residue H272, which was assigned as part of a phosphate binding site in a previous study31, is highlighted (magenta). For hEndoU, XendoU, and Nsp15, the N-terminal extension upstream of the catalytic core is highlighted (skyblue). For the model of calcium-activated, RNA-bound hEndoU, calcium ions are shown (palegreen).
