FIGURE 1.

Amino Acid sequence alignment of phox domains and domain architecture of the mammalian sorting nexin family. A, comparative sequence alignment of PX domains for residues equivalent to Gly⁴⁹–Leu¹¹⁹ of the p40-PX domain (adapted from Worby and Dixon (21)). Prolines in the Pro-X-X-Pro motif are highlighted in yellow, and residues involved in phospholipid binding in the p40-PX domain are boxed in magenta. Arg⁵⁸ and Arg¹⁰⁵ are marked with magenta triangles, and Tyr⁵⁹ and Lys⁹² are marked with black stars at the bottom of the sequences. The two conserved Arg residues and Lys⁹² of p40-PX in other PX domains are highlighted in dark blue boxes; those corresponding to Tyr⁵⁹ are boxed in green. The secondary structure elements of p40-PX are indicated by yellow arrows (β-sheets) and red ovals (α-helices). The three sequence stretches that are unique in SNX5-PX (or SNX6-PX) are enclosed in a bright blue box. B, domain architecture of SNX family members. The four classes within the SNX family are designated as PX SNXs, PX-BAR SNXs, SH3-PX-BAR, and PX-other domain SNXs. Each individual domain is depicted in a different color and/or shape. The following domains are depicted: PX (phox), BAR (Bin-Amphiphysin-Rvs), SH3 (Src homology 3), TM (transmembrane), PXA (PX domain-associated), RGS (regulator of G-protein signaling), MIT (microtubule interacting and trafficking), B41 (band 4.1 homology), TPR (tetratricopeptide repeat), PDZ (postsynaptic protein PSD-95/SAP90, the Drosophila melanogaster septate junction protein Discs-large, and the tight junction protein ZO-1), and RA (Ras association).