Figure 8.

tub1 alleles that are synthetically lethal with tub2-201 localize to the intradimer interface. Amino acids mutated in these tub1 alleles (red) are shown on Tub1p (bottom). Tub2p is partly shown above with the tub2-201 mutant residue shown in magenta. Lateral interaction elements, α-helix H3 and M loop, are shown in yellow (Nogales et al., 1999). GTP is shown in green. The view is from the side of the heterodimer. Orientation axes: + and − show microtubule orientation; lat_H3 and lat_M show lateral sides marked by helix H3 and M loop, respectively; in and out represent the inside and the outside of the microtubule, respectively. Structure drawn using MOLSCRIPT (Kraulis, 1991).