To describe how intra-organelle SMACs collectively selforganize to stabilize the fusion pore we have measured the amount of SMAC:SMAC contacts (<0.5nm) over time. Figure shows the time evolution of 4 intra-organelle SMACs initially located above the bilayers (see inset in figure , left snapshot at t=0). During the first ≈250ns SMACs transiently bind together but rapidly reduce their mutual interactions which are replaced by SMAC:lipid ones (see inset). For the rest of the time SMAC:SMAC contacts decrease monotonically while the fusion pore is stabilized, see snapshot at t≈3.25µs with 4 SMACs inside the bilayers and 2 SMACs fully inserted in the pore (orange and red), surrounding the water channel. Therefore, as the fusion pore is stabilized SMACs coordinate around the water channel along the perpendicular axis to the bilayers in a fully extended conformation.