#Question id: 2908

The H3.H4 tetramers and H2A.H2B dimers each interact with a particular region of the DNA within the nucleosome. Which of the following statement is CORRECT regarding the characteristic binding of histones with the DNA?

I. Of the 147 bp of DNA included in the structure, the histone-fold regions of the H2A.H2B dimer interact with the central 60 bp.

II. Histone H3.H4 tetramers occupy a key position in the nucleosome by binding the middle and both ends of the DNA.

III. The amino-terminal region of H4 most proximal to the histone-fold region forms a fourth alpha helix that interacts with the final 13 bp at each end of the bound DNA.

IV. The H3.H4 tetramer associate with approximately 30 bp of DNA on either side of the central 60 bp of DNA bound by H2A.H2B dimer.

V. The two H2A.H2B dimers form the bottom part of the histone octamer located across the disc from the DNA ends.