Fig. 3. Analysis of the effects of amino acid substitutions in AtMinE1_35-141 on the interaction with AtMinD1. (A) Alignment of amino acids 120-140 of AtMinE1 with amino acids 11-33 of E. coli MinE reveals that this region of the anti-MinCD domain (AMD) is highly conserved. Asterisks indicate the amino acids substituted in this study. (B) A helical-wheel projection of amino acids 120-140 of AtMinE1. The colours indicate the effects of mutations on the BD-AtMinE1_35-141 and AD-AtMinD1 interaction in yeast two-hybrid assays. BD-AtMinE1_35-141 and AD-AtMinD1 were expressed in HF7c yeast cells and monitored for growth on synthetic drop-out media lacking tryptophan and leucine (–TL) and synthetic drop-out media lacking tryptophan, leucine and histidine (–HTL). Relative interaction strengths are represented as two classes based on the ratio of growth on –TL to growth on –HTL media: red, ratio of >0.8; blue, ratio equal to the relevant control (<0.3 in all cases); black, not tested. The letters a-g represent the positions of the amino acids in the helical wheel.