Fig. 5: Intermolecular interfaces of TPX2α5-α7 with polymerized microtubules.
From: Structural basis of protein condensation on microtubules underlying branching microtubule nucleation
a 2D double-REDOR (dREDOR) filtered 1H-13C HETCOR spectrum of deuterated U-[13C,15N]-TPX2α5-α7/MT assembly. Backbone and side chain correlations are shown in black and orange, respectively. b Residues comprising the interface with MTs mapped on the TPX2α5-α7 primary sequence. c Structural model of TPX2α5-α7 bound to MT filaments, generated by blind docking of MAS NMR structure of TPX2α5-α7 onto the cryo-EM structure of polymerized MTs (PDB: 3J6G94) in ClusPro91. TPX2α5-α7 (teal) binds to MTs at the intersection between neighboring tubulin heterodimers and at the groove between two adjacent MT protofilaments, with Eg5 region (magenta) remaining exposed. d Predominant binding mode of TPX2α5-α7 (light teal) on a βα tubulin dimer in microtubule filaments. The structural model was generated from the NMR restraint-guided docking in HADDOCK92. The residues comprising the binding interface are colored orange. The functional regions and FKARP/FKAQP segments are colored light magenta. The γ-TuNA a and b motifs are positioned facing away from the MT, which allows their direct interactions with the 2.2 MDa γ-TuRC and recruit it for MT nucleation.
