Figure 1.

Alignment of the deduced amino acid sequences of ECA1 from Arabidopsis and of rabbit SERCA 2a (SER) (27) illustrates the conserved domains of P-type Ca²⁺-ATPases. The potential phosphorylation site (Asp-383) and two regions (533–536 and 727–740) that form the putative ATP-binding domain (underlined in bold) are located in the central hydrophilic loop. Each TM region is indicated with a line above the ECA1 sequence and a line below the corresponding SERCA TM domain. Potential Ca²⁺-binding sites (E³⁴¹, E⁸⁰⁰, N⁸²⁵, T⁸²⁸, D⁸²⁹, E⁹⁶¹) within predicted TM4, -5, -6, and -8 in ECA1 correspond to residues (marked with an asterisk below the residue) required for Ca²⁺ transport in rabbit SERCA pump (28). Residues sharing identity or similarity are denoted by | and :, respectively. Spaces shown as periods were introduced to maximize the alignment. The alignment was performed with gap in the Wisconsin Package gcg program.