[Balgair]

Genetics for one. If a DNA primer-pair is looking for it's complement [0], then this strategy could be useful. Here the prisoners are the complementary primers and the DNA-sequence-to-be-matched-to is the cabinet. Shepherding proteins/histones could restrict in a nucleic bottleneck of some sort, such that only one primer gets to go at once without repeating [1]. Only when the primers are all set-up is the DNA 'free' to be transcribed or some such thing.

[0] For a sequence like ATGC, the primer is the opposite nucleotide, therefore the 'matching number' would be not ATGC as well, but TACG.

[1] Look, bio is weird, like, jumping genes are actually a thing. This set-up, though strange, is not as unreasonable as a lot of stuff that goes on.