Figure 2

Identification of transmembrane domains vs cytosolic or luminal domains of SPCA1. For simplicity, SPCA1a (NP_055197) has been represented; other isoforms have identical sequence until the C-terminal tail. The highlighted codons in green and in red are the starting and stop codon, respectively. Highlighted in yellow is the first codon of each corresponding numbered exon. Highlighted in gray is the transmembrane domain. The highlighted amino acids in purple are cytoplasmic, whereas those highlighted in blue are luminal. The highlighted amino acids in azure represent the cytosolic C-terminal tail (underlined is the KXD/E motif putative COPI-binding site). The bold typed red and blue amino acids are the residues directly involved in the binding of Ca²⁺/Mn²⁺ and Mg²⁺, respectively. Of note, the putative COPI-binding motif KXD/E is just below the M10 domain. The prediction of these domains/residues was solved by similarity (UniProt database)