title: Inverted repeats in the DNA of Streptomyces plasmids pMG110 and pMG120.
abstract: Two cryptic plasmids pMG110 (10.5 kb) and pMG120 (14.5 kb) isolated from Streptomyces luteolutescens were cleaved by restriction endonucleases Bg/II, KpnI, and SalGI. A physical map was constructed for pMG110. After denaturation and intrastrand reannealing, two types of snap-back structures were identified by electron microscopy, differing in the size of the loop (type 1, 1 kb; type 2, 1.6 kb), whereas the stem of both structures was about 190 bp long. Stem-loop structures of similar size were also observed in pMG120. In rare cases, both types of elements were present on the same DNA molecule. The analysis of Bg/II- and KpnI-generated fragments allowed the localization of the elements at two alternative positions on the physical map of pMG110.
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology; D004262:DNA Restriction Enzymes; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics*; D009690:Nucleic Acid Conformation; D010957:Plasmids; D012091:Repetitive Sequences, Nucleic Acid; D013302:Streptomyces / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004262:DNA Restriction Enzymes