Fig. 6. Functional conservation of AtMinE1. (A) AtMinE1 partially complements a minE^– E. coli mutant. Cells were examined by microscopy after growth in 0.05 mM IPTG or 4 mM IPTG. minB::Kan^RP_lacMinCD/P_addA-vector control cells show a filamentous phenotype 3 hours after MinCD induction. minB::Kan^RP_lacMinCD/P_addA-AtMinE1 are, on average, shorter and symmetric (black arrowheads) and asymmetric septation events (black arrows) and minicell formation (white arrows) are observed. Cell length was measured using ImageJ software and WT cell length estimated from the average length of 100 minE⁺ cells. The lengths of >100 cells are represented graphically. (B) The localisation of the AtMinE1 domains in E. coli. Expression of the fusion proteins was induced using 0.05 mM IPTG and single-plane images of YFP captured from cells containing the empty pRSET-A vector (P_T7), expressing YFP alone (P_T7-YFP) or AtMinE1, AtMinE1_1-197, AtMinE1_1-169, AtMinE1_1-141, TP.AtMinE1_117-229 and TP.AtMinE1_142-229 fused to YFP or CFP. (C) Affect of expression of AtMinE1 truncations on E. coli cell-division phenotypes. Cells containing the empty pRSET-A vector (P_T7), or expressing YFP alone (P_T7-YFP) or AtMinE1, AtMinE1_1-197, AtMinE1_1-169, AtMinE1_1-141, TP.AtMinE1_117-229 and TP.AtMinE1_142-229 fused to YFP or CFP were induced with 2 mM IPTG. Symmetric (black arrowheads) and asymmetric septation events (black arrows) and minicell formation (white arrowheads) are observed. Bars, 2 µm.