Answer: Histones
Step-by-step explanation:
Histones are the proteins that are found in the eukaryotic cells. As the size of the eukaryotic nucleus is long it is required to be tightly packed. The histone proteins aid in the packaging of DNA inside the structural units called nucleosomes. These proteins help in maintaining the shape of the chromosome. These act as a spool around the DNA winds and play an important role in gene regulation.