FIGURE 1.

Secondary structure-based sequence alignment of human RGS-PX proteins SNX13, SNX14, SNX19, and SNX25. Secondary structure predictions calculated with JPRED (30) are indicated for SNX13 (above) and SNX19 (below). For the region encompassing the SNX19 PX domain, secondary structure information is derived from the crystal structure. The alignment was made with ESPript 2.2 (49). In addition to the four conserved domains, SNX13 and SNX25 possess an additional region with the predicted helical structure designated here as PXA′ that lies between the PXA and RGS domains. SNX19 lacks a predicted RGS domain.