Figure 2.

(a) Overall structure of the acostatin heterodimer represented by a C^α tracing of subunits A (in blue) and B (in magenta) with disulfide bridges in yellow and the side chains of the RGD binding loops. (b) Superimposition of the C^α tracing of the acostatin ABCD subunits (A subunit in green, B in blue, C in purple and D in orange). (c) Superimposition of the C^α tracing of acostatin AB (green) and CD (blue) dimers on the dimer from E. carinatus (red). (d) Overall structure of the tetrameric arrangement of all acostatin subunits represented by a C^α tracing. (e) The electrostatic surface of the acostatin tetramer on the scale ±10 kT/e. The color map is from red (negative electrostatic potential) to blue (positive electrostatic potential). The figure was prepared in PyMOL (DeLano, 2002 ▶) and the electrostatic potential was calculated using APBS (Baker et al., 2001 ▶).