Which of the following is NOT a component of nucleotides?

Nucleotides are the basic building blocks of nucleic acids, such as DNA and RNA. Each nucleotide consists of three primary components: a nitrogenous base, a five-carbon sugar, and a phosphate group. The nitrogenous bases include adenine, guanine, cytosine, and thymine (or uracil in RNA). The five-carbon sugar can either be ribose (in RNA) or deoxyribose (in DNA). The phosphate group links the nucleotides together into strands of DNA or RNA.

Histone proteins are not components of nucleotides; rather, they are proteins that facilitate the packaging of DNA into a compact, structured form known as chromatin. They play a crucial role in the regulation of gene expression and the overall structure of the genome, but they do not form part of the nucleotide structure itself.

Thus, among the options provided, the component identified as histone proteins is correctly noted as not being a part of the nucleotide structure.