Kinetics of Ribonucleic Acid Synthesis on Deoxyribonucleic Acid Template

Abstract

THE purpose of this communication is to propose a mechanism, and to establish on its basis a system of equations, for the description of the kinetics of the synthesis of ribonucleic acid (RNA) templated by deoxyribonucleic acid (DNA). The models proposed¹ for the kinetics of the DNA synthesis cannot be extended to the RNA synthesis, since they assume that the uncoiling of the DNA double helix is the rate determining step. The time required for the unwinding of a DNA molecule with a length of 10⁴ nucleotide pairs is of the order of about 30 sec (ref. 1). The in vivo synthesis rate for RNA is experimentally found to be much larger. It is therefore reasonable to assume that, in contrast to the replication of the DNA molecule, the RNA synthesis does not require the unwinding of the whole DNA double helix but only of a short part of it.