Fig. 2. Sequence analysis of IP₃R_N. Alignment of PtIP₃R_N and rat Ins(1,4,5)P₃R3 (RnIP₃R3) using the `Blast 2 Sequences' tool (Tatusova and Madden, 1999). Sequences are shown in single-letter code and are numbered on the left side. Residues that are identical are shaded black, similar residues are shaded gray. The putative binding region for Ins(1,4,5)P₃ is boxed in yellow. Amino acids shaded blue are involved in Ins(1,4,5)P₃-binding, those bordered in dark blue are essential for Ins(1,4,5)P₃-binding (Yoshikawa et al., 1996). The homology domain for Ins(1,4,5)P₃Rs and RyRs (RIH-domain) is boxed in green, the channel domain in light blue. The six transmembrane regions are highlighted in red, the pore region in yellow. The antigenic region used to raise a polyclonal Ab is boxed in gray. Rat Ins(1,4,5)P₃R3 sequences (accession number L06096) are published by Blondel et al. (Blondel et al., 1993).