B H359 and E363 in Myc establish H-bonds with the complementary G6 and C1' bases, respectively, E363 forming an additional bond with A2. R364, R366 and R367 contact the phosphodiester backbone, R367 interacting also with G4. Note that, in keeping with the symmetric configuration of the Myc/Max dimer (panel A) and with the similar structure of the Max homodimer (Ferre-D'Amare et al., 1993), the corresponding residues in Max (R33/35/36, and H28/E32) form equivalent contacts with the other half of the E-box palindrome. 