Stoichiometry and accessibility of histone 3 sulfhydryl groups in chromatin subunits

The accessibility of the sulfhydrl groups of histone 3(H3) in chromatin subunit particles has been investigated by reaction with p-hydroxymercuribenzoate. The resuls indicate that the carboxy-terminal regions of H3 are buried in the native particle, and suggest the presence of 2 mol of H3 per chromatin monomer.