Subunit interface This shows the gamma subunit (blue) and the epsilon subunit (green) of the ATP synthase. At the bottom, notice that a beta strand from gamma has joined one 5-stranded beta-sheets of epsilon. Also, 5 water molecules (red) are shown at the interface of the 2 subunits. Wilce, M. C. J., Rodgers, A. J. W.: Structure of the G-E Complex of ATP Synthase Nat.Struct.Biol. 7 pp. 1051 (2000) (PubMed) 1fs0 (PDB)