Fig. 5: Structural basis of Aurora B autophosphorylation mechanism via the phosphorylation of T236.

a The superposed crystal structures of human and Xenopus Aurora B proteins that are colored in white and gray, respectively. The activation loops in human and Xenopus Aurora B are in red and green, respectively. A yellow arrow indicates the positional difference between identical helices highlighted by circles. b Structural arrangement of Asp200, Lys202, Thr232, and Thr236 in the crystal structure of the Xenopus Aurora B-INCENP complex (PDB code: 2BFX). The activation loop is colored in green. Black dashed lines between residues in sticks represent distances. Nitrogen and oxygen atoms in sticks are colored in blue and red, respectively. c The putative interaction mode among Asp200, Lys202, and pThr236. A red arrow represents the electrostatic repulsion, whereas a black dashed line does an electrostatic interaction. d The putative interaction mode among Asp200, Lys202, and Ala236 when Thr236 is mutated to alanine. Black dashed lines between residues in sticks represent distances. e Floating mitotic cells were obtained after nocodazole treatment for 4 h and subjected to immunofluorescence image: pT232-Aurora B (green), HA (red), and DAPI (blue). Bars represent mean ± SEM from three independent experiments; WT n = 22, T236A n = 28, D200A n = 38, nK202A = 34 cells. Scale bar, 5 μm. f HA-Aurora B WT or D200A/K202A mutants were transfected in Aurora B-depleted cells and analyzed by immunoblotting. Data of f are representative of two independent experiments. Source data are provided as a Source Data file.