SMC complexes organize the bacterial chromosome by lengthwise compaction

Mäkelä, Jarno; Sherratt, David J.

doi:10.1007/s00294-020-01076-w

Cited by 30 publications

(25 citation statements)

References 32 publications

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“…SMC complexes were shown to move along bacterial chromosomes from the centrally positioned origin of replication ( oriC ), leading to gradual chromosome compaction and parallel alignment of both replichores 5 , 6 , 24 , 25 . Importantly, although the alignment of two chromosomal arms was not seen in E. coli , the MukBEF complex is still responsible for long-range DNA interactions 10 , 26 .…”

Section: Introductionmentioning

confidence: 99%

Spatial rearrangement of the Streptomyces venezuelae linear chromosome during sporogenic development

et al. 2021

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Bacteria of the genus Streptomyces have a linear chromosome, with a core region and two ‘arms’. During their complex life cycle, these bacteria develop multi-genomic hyphae that differentiate into chains of exospores that carry a single copy of the genome. Sporulation-associated cell division requires chromosome segregation and compaction. Here, we show that the arms of Streptomyces venezuelae chromosomes are spatially separated at entry to sporulation, but during sporogenic cell division they are closely aligned with the core region. Arm proximity is imposed by segregation protein ParB and condensin SMC. Moreover, the chromosomal terminal regions are organized into distinct domains by the Streptomyces-specific HU-family protein HupS. Thus, as seen in eukaryotes, there is substantial chromosomal remodelling during the Streptomyces life cycle, with the chromosome undergoing rearrangements from an ‘open’ to a ‘closed’ conformation.

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Section: Introductionmentioning

confidence: 99%

Spatial rearrangement of the Streptomyces venezuelae linear chromosome during sporogenic development

et al. 2021

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“…Associations between molecules due to their topology are known as mechanical bonds (Stoddart, 2009). In eukaryotes as well as prokaryotes, ring-like SMC complexes are thought to structure chromosomes via mechanical bonds with DNA (also referred to as 'DNA entrapment'), and active DNA loop extrusion (Davidson and Peters, 2021;Hassler et al, 2018;Mäkelä and Sherratt, 2020a;Nasmyth, 2001;Yatskevich et al, 2019). These activities have been suggested to enable or facilitate processes such as lengthwise condensation of chromosomes, sister chromatid cohesion, regulation of interactions between enhancers and distant promoters, disentangling of replicated DNA by topoisomerases, DNA recombination, and DNA double-strand break repair.…”

Section: Introductionmentioning

confidence: 99%

Cryo-EM structure of MukBEF reveals DNA loop entrapment at chromosomal unloading sites

uumlrmann

Funke

Chin

et al. 2021

Preprint

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The ring-like structural maintenance of chromosomes (SMC) complex MukBEF folds the genome of Escherichia coli and related bacteria into large loops, presumably by active DNA loop extrusion. MukBEF activity within the replication terminus macrodomain is suppressed by the sequence specific unloader MatP. Here we present the complete atomic structure of MukBEF in complex with MatP and DNA as determined by electron cryomicroscopy (cryo-EM). The complex binds two distinct DNA double helices corresponding to the arms of a plectonemic loop. MatP-bound DNA threads through the MukBEF ring, while the second DNA is clamped by the kleisin MukF, MukE and the MukB ATPase heads. Combinatorial cysteine cross-linking confirms this topology of DNA loop entrapment in vivo. Our findings illuminate how a class of near-ubiquitous DNA organizers with important roles in genome maintenance interacts with the bacterial chromosome.

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“…Importantly, although the alignment of two chromosomal arms was not detected in E. coli, the MukBEF complex is still responsible for the long-range DNA interactions within chromosomal domains 10,26 .…”

Section: Introductionmentioning

confidence: 96%

Spatial rearrangement of theStreptomyces venezuelaelinear chromosome during sporogenic development

Szafran

Małecki

Strzałka

et al. 2020

Preprint

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Depending on the species, bacteria organize their chromosomes with either spatially separated or closely juxtaposed replichores. However, in contrast to eukaryotes, significant changes in bacterial chromosome conformation during the cell cycle have not been demonstrated to date. Streptomyces are unique among bacteria due to their linear chromosomes and complex life cycle. These bacteria develop multigenomic hyphae that differentiate into chains of unigenomic exospores. Only during sporulation-associated cell division, chromosomes are segregated and compacted. In this study, we show that at entry to sporulation, arms of S. venezuelae chromosomes are spatially separated, but they are closely aligned within the core region during sporogenic cell division. Arm juxtaposition is imposed by the segregation protein ParB and condensin SMC. Moreover, we disclose that the chromosomal terminal regions are organized into domains by the Streptomyces-specific protein - HupS. Thus, we demonstrate chromosomal rearrangement from open to close conformation during Streptomyces life cycle.

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SMC complexes organize the bacterial chromosome by lengthwise compaction

Cited by 30 publications

References 32 publications

Spatial rearrangement of the Streptomyces venezuelae linear chromosome during sporogenic development

Spatial rearrangement of the Streptomyces venezuelae linear chromosome during sporogenic development

Cryo-EM structure of MukBEF reveals DNA loop entrapment at chromosomal unloading sites

Spatial rearrangement of theStreptomyces venezuelaelinear chromosome during sporogenic development

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