Figure 6

Comparison of the α1 and α2 regions of the MHXs, NCXs and CrNCX. A. The α1 and α2 regions of NCX proteins (as defined in [36]) were aligned. The comparable regions of MHX proteins and CrNCX were also aligned. All alignments were done manually. The sequences shown for the α1 and α2 regions of MHX and NCX are the consensus of each protein family in these regions. Uppercase letters indicate totally conserved residues, lowercase letters indicate the most common residue at each position, dots indicate residues for which there was no clear consensus, and dashes indicate gaps introduced to facilitate the alignments. The bold, underlined dot in the α1 of NCX1 indicates where three other dots were removed to simplify the alignment. White letters highlighted in black indicate residues conserved in the corresponding α1 and α2 positions of most or all proteins of each family. Letters highlighted in light gray represent residues with a similar nature in the corresponding α1 and α2 positions. The lower lines (Cons.) indicate the consensus sequence of the α1 and α2 regions of each protein family. Residue types were defined as: @ - aromatic (F, W, Y, or H); u - aliphatic (I, L, or V); 1 - basic (H, K, or R); 2 - acidic (D or E); p - charged (acidic or basic); $ - hydroxylic (S or T); m - methyl (A, S, or C,); o - small (G, A, S, or C). B. All the above indicated α1 and α2 regions were aligned together manually. White letters highlighted in black indicate residues that are conserved in the corresponding α1 and α2 positions of most or all MHX and NCX proteins. Letters highlighted in light gray represent positions in which there is a somewhat lower conservation. The lower line (Cons.) indicates the consensus sequence of the α1 and α2 regions of all the investigated MHXs and NCXs, as well as CrNCX. See text for explanation of the yellow highlighted letters.