Final answer:
The nucleosome core particle consists of four different types of histones: H2A, H2B, H3, and H4. Two copies of each create an octamer, around which DNA wraps to form a nucleosome.
Step-by-step explanation:
The content loaded question about how many types of histones are in the nucleosome core particle can be addressed by understanding the structure of nucleosomes. Nucleosomes are part of the compaction strategy employed by eukaryotic cells to fit DNA within the nucleus in a highly organized manner. The core of a nucleosome is made of proteins called histones, which are evolutionarily conserved and rich in basic amino acids like lysine and arginine.
These histones form an octamer composed of two copies each of four different types of histones: H2A, H2B, H3, and H4. The DNA wraps around this histone octamer, creating a bead-like structure. In addition to these four core histones, there is also a fifth histone called H1, which is not part of the core but is involved in the further compaction of chromatin structure. Therefore, the number of different types of histones in the nucleosome core particle is four.