FIGURE 1.
Structural analysis of the function of Gαil residue asparagine 149 in mediating the interaction between Gαi1·GDP and the GoLoco motif of RGS14. Ribbon diagram of the RGS14 GoLoco motif (blue) bound to Gαi1·GDP (yellow). Gα residues are annotated in red; GoLoco motif residues are annotated in blue, and bound GDP is colored magenta. A, overall view of the complex highlighting the position of the αD/αE helix. Asn149 is highlighted in stick format (red). B, enlarged view of the Gα/GoLoco motif interaction interface. The side chain oxygen of Gln515 forms a hydrogen bonding network with the side chain and backbone amine of Asn149. C, enlarged view of intramolecular interactions of Asn149. The side chain amine of Asn149 forms a hydrogen bond with the side chain oxygen of Ser80. Asn149 also makes several stabilizing contacts with Arg178, predominantly between the α-carbon of Asn149 and the ζ-carbon of Arg178.