Structural analysis of EB-CH domains. (A) Sequence alignment of the three human EB homologues. Residue assignment and secondary structure elements are indicated on the top of the alignment. Residues colored in red and green indicate the differences between EB3 and EB2 (EB2 sequence) and EB3 and EB1 (EB1 sequence), respectively. Residues highlighted in blue in the EB1 sequence were shown to affect MT association in cells; in gray, residues that do not affect MT binding (Slep and Vale, 2007). (B) X-ray crystal structure of EB3-CH domain (yellow ribbon) overlaid onto the ones of EB1 (green ribbon; PDB entry 1pa7) and Bim1 (magenta ribbon; PDB entry 2qjx). (C and D) Two views of the EB3-CH domain, 150° apart and in surface representation. EB3 residue assignments are indicated. Both panels depict sequence differences between EB3 and EB2 and between EB3 and EB1. The color code is the same as in (A) with the addition that simultaneous residue changes in both EB1 and EB2 are indicated in orange if it is unknown whether they influence MT binding, light orange if they do not affect MT binding, and in purple if they do (Slep and Vale, 2007).