Figure 1.

Predicted secondary structure and topology of human prestin based on the model previously described by Zheng et al. (2001, 2005, 2006). The location of the 12 transmembrane domains is based on Olivier et al. (2001) and Rajogopalan et al. (2006). Transmembrane domain 2 in blue contains the sulfate motif defining the family. The properties of the amino acid side chains are indicated by different colors: polar (white), non-polar (blue), acidic (red), basic (green), and cysteine residues (yellow). Mutations utilized to generate knockin mouse models with modified prestin function (Dallos et al., 2008; Gao et al., 2007) are indicated with black arrows. Note that in the model by Gao et al (2007) residues K233, K235 and R236 are intracellular. Positive-selected amino acids in mammals detected by the evolutionary analysis performed by Franchini and Elgoyhen (2006) are highlighted with red circles and indicated with red arrows. Positive selected amino acids in echolocating bats detected by Li et al. (2008) are highlighted by violet circles and indicated with violet arrows. Positive selected amino acids in bats that co-evolved in dolphins display an additional green circle.