DNA Kromatin - Kromozom bacteial nucleoid Architectural model of the bacteial nucleoid The DNA and histone-like proteins (HU, IHF, H-NS, etc.) form a nucleosome-like structure, which is further folded into a 40-nm fiber. The 40-nm fiber is super-solenoided into an 80-nm fiber with oth er nucleoid-related proteins. The 80-nm fiber forms a loop structure.