We consider DNA translocation through a narrow pore in a membrane, which fits only one DNA segment. For an idealized model with force $f$ acting only inside the pore on a very long and flexible polymer, we modify the previously developed treatment of the deformed part of the pre-translocated polymer by introducing the concept of ``iso-flux trumpet''. Unlike the speed of the process which is determined by the friction of the trailing part, the dominant dissipative mechanism is due to irreversible entropic squeezing of the chain during the process. We also discover that the presence of membrane causes an energy transfer of order $k_B T$ per monomer from the heat bath on post-translocation to the heat bath on pre-translocation side of the membrane.
View poster as pdf.
Author entry (protected)