Fig. 1.

Overview of the HMA4 variant constructs for complementation experiments in plants. The expression cassettes are schematically represented. The nucleotide sequences encoding A. thaliana (dark gray) or A. halleri (light gray) native or mutant HMA4 proteins are preceded by the A. thaliana HMA4 promoter (pAt, 2595 bp). Numbers correspond to the amino acid position in the HMA4 protein. Ah, A. halleri; At, A. thaliana; AtAhHMA4 and AhAtHMA4, swapped C-terminal extensions; HA: His- → Ala-stretch; CCAA: di-Cys → di-Ala motifs; CHA: HA and CCAA mutations combined; Ctrunc: fully truncated C-terminal extension.