Chemical Knowledge

• determination of atom types in arbitrary molecules, including non-standard residues
• ability to add hydrogen atoms
• high-quality hydrogen bond identification
• selection of atoms/bonds by element, atom type, functional group, amino acid category
• interactive bond rotation, distance and angle measurements

Heterotrimeric G protein (Protein Data Bank entry 1gg2) with the alpha subunit shown in green, the beta subunit in light blue, and the gamma subunit in brown. The Intersurf tool was used to show the interface between the alpha and beta subunits. The interface surface is colored to show the distance between atoms across the interface (red for closer together, blue for farther apart). (More samples...)