Mixed oligomers, representing oligonucleotides connected with long non-nucleotide spacers, have been synthesized using phosphoramidite chemistry. The oligonucleotide moieties of the mixed oligomers fully or partially correspond in the structure to the
consensus elements of -35 (TTGACA) and -10 (TATAATG) regions of prokaryotic promoters. The non-nucleotide spacers, approximating in size 17-membered DNA fragments, were synthesized using phosphoramidite derivatives of polyethylene glycol (PEG600), tetraethylene glycol or dodecanediol. It is shown that the oligonucleotide moieties of the mixed oligomers can form \"normal\" DNA like antiparallel complementary complexes, being the substrates of T4 DNA ligase. To obtain the DNA-like polymers with alternating natural and non-natural regions or cyclic structures, the enzymatic ligation of different complexes of the oligomers synthesized was studied.