Description: 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.
*Histone H2B contains a glutamate-to-alanine (E-to-A) substitution at positions 105 and 113 (H2BE105A,E113A). H2BE105 and H2BE113 are 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. H2B E105 and E113 both reside in the H2B alphaC extension and are associated with nucleosome binding factors such as histone H4 N-terminal tail, LANA, RCC1, HMGN2 and SMARCB1.