Kinetics of DNA-dependent RNA synthesis: couple synthesis of di-, tri- and tetranucleotides in the presence of a limited set of substrates

The qualitative and quantitative characteristics of the short oligonucleotides synthesis by Escherichia coli RNA polymerase on A1 promoter of the bacteriophage T7 in the presence if incomplete set of nucleoside triphosphates were studied. The binding of the fourth substrate with enzyme-template complex was shown to occur after binding of the third substrate only. The curves of di-, tri- and tetranucleotide synthesis as the function of CTP and GTP concentration were constructed. The empiric formulas for the rates of the coupled synthesis if tri- and tetranucleotides were derived from these curves. A kinetic scheme describing the experimental data was proposed.