title: pSAR1, a natural plasmid from Streptomyces arenae, shows rapid increase and decrease of copy numbers on changes of growth media.
abstract: A natural plasmid, pSAR1, was isolated from the antibiotic producer Streptomyces arenae TU469. Its size is estimated to approx. 80 kbp by restriction analysis. pSAR1 occurs in two copy-number states differing by a factor of at least 10, depending on culture conditions. The high copy-number state is strongly correlated with the production of the antibiotic pentalenolactone. The decrease of copy numbers after change of culture conditions is completed within 1 h. These unusually rapid kinetics and the occurrence of degradational intermediates suggest the participation of specific catalytic mechanisms in copy number regulation.
authors.affiliation: Physiologisch-chemisches Institut, University of Tübingen, F.R.G.
authors.forename: M
authors.initials: M
authors.lastname: Braxenthaler
authors.forename: B
authors.initials: B
authors.lastname: Poetsch
authors.forename: K U
authors.initials: KU
authors.lastname: Fröhlich
authors.forename: D
authors.initials: D
authors.lastname: Mecke
mesh_terms: D003470:Culture Media; D004269:DNA, Bacterial / Q000378:metabolism; D005784:Gene Amplification; D007700:Kinetics; D010957:Plasmids; D013302:Streptomyces / Q000235:genetics* / Q000254:growth & development
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial