The rise and fall of the 30 nm fiber
Although the structure of the nucleosome has been solved with atomic resolution, higher-order structures of chromatin remain ill-defined and are still controversial. It was book knowledge for ages – and I was also told so in my own biochemistry lectures – that nucleosomes (i.e. the beads-on-a string structure or the 10 nm fiber) fold and assemble into higher order structures until chromosome-level of compaction is achieved. In this model, the 30 nm fiber represents the next level of compaction. [...]