Complexes of DNA with arginine-rich and slightly lysine-rich histones. Transcription and electron microscopy.

Calf thymus DNA was reconstituted with arginine-rich histones H3 and H4 and slightly lysine-rich histones H2A and H2B respectively. Complexes containing histones H3 and H4 exhibit nucleosome-like structures when examined in the electron microscope and show a restriction of in vitro transcription similar to that obtained for reconstitutes made up from the four histones H2A, H2B, H3 and H4. One the contrary, complexes of DNA and histones H2A and H2B create different morphological structures of short stretches of bound histones and do not cause a template restriction in vitro.