title: Spontaneous chromosome circularization and amplification of a new amplifiable unit of DNA belonging to the terminal inverted repeats in Streptomyces ambofaciens ATCC 23877.
abstract: In Streptomyces, the linear chromosomal DNA is highly unstable and undergoes large rearrangements usually at the extremities. These rearrangements consist of the deletion of several hundred kilobases, often associated with the amplification of an adjacent sequence, AUD ( amplifiable unit of DNA). In Streptomyces ambofaciens, two amplifiable regions (AUD6 and AUD90), located approximately 600 kb and 1,200 kb from the right chromosomal end respectively, have been characterized. Here, the isolation and molecular characterization of a new S. ambofaciens mutant strain exhibiting a green-pigmented phenotype is described; the wild-type produces a gray pigment. In this mutant, both chromosome ends were deleted, which probably led to circularization of the chromosome. These deletions were associated with amplification of a sequence belonging to the chromosomal terminal inverted repeats (TIRs), which might constitute the new fragment generated by the chromosomal circularization.
authors.affiliation: Laboratoire de Génétique et Microbiologie (UMR INRA/UHP 1128), IFR 110, Faculté des Sciences de l'université Henri Poincaré-Nancy 1, BP239, 54506 Vandoeuvre-lès-Nancy, France.
authors.forename: Sibel
authors.initials: S
authors.lastname: Catakli
authors.forename: Axelle
authors.initials: A
authors.lastname: Andrieux
authors.forename: Pierre
authors.initials: P
authors.lastname: Leblond
authors.forename: Bernard
authors.initials: B
authors.lastname: Decaris
authors.forename: Annie
authors.initials: A
authors.lastname: Dary
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D002872:Chromosome Deletion; D002876:Chromosomes, Bacterial / Q000737:chemistry* / Q000235:genetics*; D015342:DNA Probes; D004269:DNA, Bacterial / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016521:Electrophoresis, Gel, Pulsed-Field; D008957:Models, Genetic; D009154:Mutation; D010860:Pigments, Biological / Q000737:chemistry; D012303:Ring Chromosomes; D013302:Streptomyces / Q000235:genetics* / Q000302:isolation & purification; D020079:Terminal Repeat Sequences
chemical_list: D001426:Bacterial Proteins; D015342:DNA Probes; D004269:DNA, Bacterial; D010860:Pigments, Biological