Spontaneous chromosome circularization and amplification of a new amplifiable unit of DNA belonging to the terminal inverted repeats in Streptomyces ambofaciens ATCC 23877

Catakli, Sibel; Andrieux, Axelle; Leblond, Pierre; Decaris, Bernard; Dary, Annie

doi:10.1007/s00203-003-0534-7

Cited by 7 publications

(2 citation statements)

References 23 publications

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“…Chromosome circularization, via recombination between sequences near the ends (19,60), is only one of the structural changes undergone by Streptomyces chromosomes. Robinson et al (97) described variants carrying a 6-kb sequence tandemly amplified ∼300 times, and many other reports followed, some very detailed.…”

Section: Genome Instabilitymentioning

confidence: 99%

Soil To Genomics: The Streptomyces Chromosome

2006

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The 8-9-Mb Streptomyces chromosome is linear, with a "core" containing essential genes and "arms" carrying conditionally adaptive genes that can sustain large deletions in the laboratory. Bidirectional chromosome replication from a central oriC is completed by "endpatching," primed from terminal proteins covalently bound to the free 5 -ends. Plasmid-mediated conjugation involves movement of double-stranded DNA by proteins resembling other bacterial motor proteins, probably via hyphal tip fusion, mediated by these transfer proteins. Circular plasmids probably transfer chromosomes by transient integration, but linear plasmids may lead the donor chromosome end-first into the recipient by noncovalent association of ends. Transfer of complete chromosomes may be the rule. The recipient mycelium is colonized by intramycelial spreading of plasmid copies, under the control of plasmid-borne "spread" genes. Chromosome partition into prespore compartments of the aerial mycelium is controlled in part by actin-and tubulin-like proteins, resembling MreB and FtsZ of other bacteria.

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Section: Genome Instabilitymentioning

confidence: 99%

Soil To Genomics: The Streptomyces Chromosome

2006

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“…In most cases well‐characterized, amplification is associated with the deletion of all the sequences from the amplified locus to the end of the chromosome, the chromosomal DNA remaining linear (Rauland et al ., 1995; Fischer et al ., 1997a). In contrast, amplification associated with circularized chromosomes has been only rarely reported (Redenbach et al ., 2000; Catakli et al ., 2003).…”

Section: Introductionmentioning

confidence: 99%

End‐to‐end fusion of linear deleted chromosomes initiates a cycle of genome instability in Streptomyces ambofaciens

Wenner

Roth

Fischer

et al. 2003

Molecular Microbiology

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SummaryTwo mutant strains harbouring a linear chromosome whose size reached 13 Mb (versus approximately 8 Mb for the wild type) were characterized. This chromosomal structure resulted from the fusion in inverted orientation of two chromosomes partially deleted on the same arm. The fusion occurred by illegitimate recombination between 6 bp repeats. This chromosomal structure was inherited in strict association with a high level of genetic instability (30% of mutants in a single progeny, phenomenon also called hypervariability) and chromosomal instability. In contrast, derivatives, which did not retain the chromosome fusion, showed a wild-type-like instability frequency ( c . 1%). Stabilization of the chromosomal structure occurred by chromosome arm replacement or circularization. A high variability of the terminal inverted repeat (TIR) length in the rescued chromosomes (from 5 kb to approximately 1.4 Mb for linear derivatives) was observed. Mutant lineages harbouring the chromosomal fusion are characterized by a highly heterogeneous distribution of DNA in the spores, by the presence of spores without DNA as well as aberrant sporulation figures, and by the production of spores with a low germination rate. The wild-type characteristics were restored in the descendants, which lost the chromosomal fusion. Thus, the fusion of deleted chromosomes initiates a cycle of chromosome instability sharing several levels of analogy with the behaviour of dicentric chromosomes in eukaryotes. We propose that the high instability of the fused chromosomes results from the duplication of a region involved in partitioning of the chromosomes ( parAB-oriC ).

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Gene Overexpression in Streptomyces hygroscopicus Associated with DNA Amplification

Cao

Zhang

et al. 2017

Curr Microbiol

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The genetics of the Streptomyces hygroscopicus strain 10-22 is of interest due to the ability of this strain to produce antifungal compounds. Strain T110 was obtained through insertional mutagenesis of strain 10-22 and was found to have undergone DNA amplification, as determined by both conventional and pulsed-field gel electrophoresis (PFGE). pIJ702, the vector used for insertional mutagenesis, was shown to have integrated into and co-amplified with the chromosomal DNA sequence of T110, as pIJ702 hybridized predominantly with two of the three amplified BamHI fragments. The amplified DNA sequence in T110 is 10.8 kb in length and consists of 5.18 kb of Streptomyces chromosomal DNA and the entire 5.62 kb pIJ702 sequence. Sequence analysis of the 5.18 kb chromosomal sequence revealed two open reading frames, one encoding a putative IS5 family transposase and the other encoding a putative dihydroxy-acid dehydratase. Real-time PCR analysis showed that expression of the putative dehydratase gene in T110 is about 50 times greater than in the wild-type strain, consistent with the high level of amplification of this DNA region, and therefore this system has the potential for producing economically or clinically important molecules.

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Spontaneous chromosome circularization and amplification of a new amplifiable unit of DNA belonging to the terminal inverted repeats in Streptomyces ambofaciens ATCC 23877

Cited by 7 publications

References 23 publications

Soil To Genomics: The Streptomyces Chromosome

Soil To Genomics: The Streptomyces Chromosome

End‐to‐end fusion of linear deleted chromosomes initiates a cycle of genome instability in Streptomyces ambofaciens

Gene Overexpression in Streptomyces hygroscopicus Associated with DNA Amplification

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