The present invention relates to nucleic acid molecules containing poly (dA:dT) regions which are stabilized in E.-coli, methods of propagating such nucleic acid molecules in E. coli, methods of obtaining RNA, peptides or proteins using such nucleic acid molecules and to RNA which is obtained from such nucleic acid molecules and its use. In particular, the poly (dA:dT) regions contain at least one disruption by a sequence not encoding a sequence solely composed of A residues.