Mononucleosomes assembled from recombinant human histones expressed in E. coli (two each of histones H2A*, H2B, H3 and H4; accession numbers: H2A-P04908*; H2B-O60814; H3.1-P68431; H4-P62805) wrapped by 147 base pairs of 601 positioning sequence DNA [1].
*Histone H2A contains a glutamate-to-lysine (E-to-K) substitution at position 92 (H2AE92K). H2AE92 is among key residues forming a negatively charged region on the nucleosome surface named the “acidic patch”. The acidic patch is a conserved interaction hub for neighboring nucleosomes and nucleosome binding proteins, often via salt bridges with arginine anchors, and is functionally critical in chromatin condensation and chromatin remodeling [2-4]. H2AE92 resides in the H2A C-terminal extension and is associated with nucleosome binding factors such as histone H4 N-terminal tail, LANA, RCC1, IL-33, SIR3, HMGN2, and remodeling ATPases [2-4]. H2AE92K disrupts binding with SMARCB1 [5].