To monitor what conformations are plausible for a membrane-embedded prenyl chain with intermediate length that still attached to h-cisPT, independent simulations were carried out where the extension was incomplete (9 prenyl units). After extension, the intermediate was found at the interface between aqueous solution and the membrane. From this starting position, five additional replicas were simulated for an additional 1 µs to sample protein-membrane orientations on the membrane for intermediate product lengths. To determine the capacity of shorter chains to form sustained interactions with the ER membrane, simulations were carried out with a 15-unit prenyl chain, which is long enough to contact the membrane surface, but shorter than the mature products produced by h-cisPT in-vivo. Simulations started from a position where the prenyl chain was in contact with the membrane. From this position, five simulations were carried out for a total of 250 ns.