Fig. 2: TM4 and TM9 of PIN1 form a crossover structure.
From: Structural insights into auxin recognition and efflux by Arabidopsis PIN1
a, An overview of the crossover structure of TM4 (cyan) and TM9 (orange). b, The crossover structure of TM4 and TM9 is stabilized by the positively charged R547 in TM8. Positions corresponding to the two sodium binding sites in ASBTNM are indicated by dashed outlines. Magnified views are shown for each site. c, PIN1 contains a cytosolic domain (cyan) composed of three β-strands. Ionic interactions between the transmembrane segments and the β1–β2 linker are shown as red dashed lines.
