The Free Energy Profile of Tubulin Straight-Bent Conformational Changes, with Implications for Microtubule Assembly and Drug Discovery
Figure 1
Conformational rearrangements of α- and β-subunits of the straight (PDB entry 1JFF [4], resolution 3.5 Å) and bent (PDB entry 1SA0 [7], resolution 3.58 Å) tubulin heterodimers.
The N-terminal nucleotide binding (residues 1–205) and C-terminal (residues 382–437) domains are rendered as grey ribbons. Helices and β-strands comprising the intermediate domain (residues 206–381) are colored blue (straight) and red (bent). We quantify curvature of the straight and bent heterodimers based on a ∼12° intradimer rotation between the α- and β-H7 helices (residues 222–244), after superimposing the α-H7 helices. Figure was generated using PyMOL [49].