Table S1.

Parameters for the contact sites of hemifused SVs with the PM

Hemifused SV no.	Average contact site thickness, nm	Average simulated thickness, nm	P	Contact site area, nm2
1	12.6 ± 2.1	15.7 ± 1.2	0.016	700
2	12.2 ± 2.6	15.8 ± 1.8	0.003	790
3	12.1 ± 2.3	15.8 ± 1.8	0.045	870
4	10.9 ± 2.5	15.9 ± 1.6	0.007	510
5	10.7 ± 2.3	15.6 ± 1.3	0.002	630
6	11.6 ± 2.4	15.4 ± 1.3	0.015	690
7	11.3 ± 2.0	16.1 ± 1.2	0.004	460

P values are derived from comparison (Bootstrap test) of the average contact site thickness and the average thickness of the simulated measurements that are based on the thickness of the SV membrane and PM away from the contact site.