Figure 1.

ARF Domains. (A) Cartoon representations of the domain organization of the three classes of ARFs, with DNA-binding domain (DBD), middle region (MR) and PB1 domains indicated. (B) Structure of the ARF1 dimerized DNA-binding domain (DBD). The left ARF1 DBD monomer is shown as a ribbon diagram whereas the right monomer is shown as a surface model. Each ARF1 DBD monomer is composed of three distinct regions: the B3 domain (pink), the dimerization domain (DD, blue), and the ancillary domain (AD, yellow). (C) ARF7 PB1 domain interactions are driven by the conserved residues on opposing positive (+) and negative (−) interaction surfaces. Detail of the ARF7 dimer interaction surface shows the conserved positive K1042 and R1051 (purple) and the negative D1092, E1094, D1096, and D1102 (red) residues that participate in charge–charge interactions.