[Reiterative poly(A) synthesis on oligonucleotide templates in an Escherichia coli RNA-polymerase system].

The poly(A) synthesis in the E. coli RNA-polymerase system on the oligothymidilates, oligouridilates and oligonucleotides d(5'-OH-CCATCTTTT-3'-OH) and d(5'-HO-TCTTTT-3'-OH) as templates was studied. The reaction was shown to proceed more intensively on the oligothymidilates compared to oligouridilates. The insertion of phosphate residues into 3' end of oligouridilates deteriorates properties of their templates though the length of the synthesized poly(A) is not changed in this case. The synthesis of poly(A) on the nonanucleotide d(CCATCTTTT) proceeds intensively, but there is no AMP incorporation on the hexanucleotide of similar structure. The author's data combined with certain literature results suppose that the template activity of the oligonucleotides containing homopolymer sequences is determined in the RNA-polymerase system in reiterative regime by two factors: by the total amount of oligonucleotide links and by the homopolymer block size. The total amount of links seems to be important for the oligonucleotide enzyme bind stability and must comprise not less than 6 charges of the phosphate groups. The homopolymer block size must be no less than of 4 links.