Figure 1.

Plant and animal G subunits have not changed in structure over the 1.6 billion years of potential evolution and show particular conservation in the structure that is important for G cycling. A, Overlay of crystal structure of the plant G subunit (AtGPA1, PDB = 2XTZ; Jones et al., 2011a) and animal (rat Gi1, PDB = 3FFB; Kapoor et al., 2009). Structure 2xTZ is shown in green and structure 3FFB is shown in magenta. The nucleotide binding and hydrolysis pocket is in the center. The overall RMSD is 1.3 Å. B, The nucleotide pocket indicated in (A) is shown in detail with a slight tilting for better view.