Template Activity of Partially Dehistonized Nucleohistones for DNA Dependent RNA Polymerase

Abstract

Histone was removed partially from calf thymus nucleohistone, and free phosphate groups not bound to histones on DNA were estimated by the toluidine blue method. The template activities of nucleohistones containing different amounts of histone for DNA dependent RNA polymerase [EC 2.7.7.6] from E. coli B (H) revealed the fact that the amount of RNA synthesized by RNA polymerase is proportional to the amount of free phosphate groups in the template but not to the amount of removed histone. The nearest neighbour frequencies of the RNAs formed with these partially dehistonized nucleohistones using [³²P)ATP and the base compositions were closely similar to each other. It was therefore suggested that histones distribute evenly along the DNA chains in the nucleohistone. Furthermore, there was found no remarkable difference in the inhibitory effect between lysine-rich and arginine-rich histones.