the catalytic domain ( amino acid residues 1 to 166 ) of the human ras-oncogene product p21 complexed with the gtp analogues beta , gamma-imido-gtp ( gmppnp ) , beta , gamma-methylene-gtp ( gmppcp ) , and guanosine-5'- ( gamma-thiotriphosphate ) ( gtp gamma s ) have been been crystallized .
C0018353
gtp
C0079469
gtp gamma s