The MukB–topoisomerase IV interaction is required for proper chromosome compaction

Kumar, Rupesh; Nurse, Pearl; Bahng, Soon; Lee, Chong Min; Marians, Kenneth J.

doi:10.1074/jbc.m117.803346

Cited by 18 publications

(23 citation statements)

References 45 publications

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“…3 b ii). Recently, it was found that the MukB-TopoIV interaction at origins in fact promoted DNA condensation and did not involve any catalytic activity of TopoIV 28 . It may therefore be that TopoIV bound to MukB at origins does not contribute to resolution of precatenanes, but instead has other roles.…”

Section: Discussionmentioning

confidence: 99%

Topoisomerase IV tracks behind the replication fork and the SeqA complex during DNA replication in Escherichia coli

Helgesen

Sætre

Skarstad

2021

Sci Rep

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Topoisomerase IV (TopoIV) is a vital bacterial enzyme which disentangles newly replicated DNA and enables segregation of daughter chromosomes. In bacteria, DNA replication and segregation are concurrent processes. This means that TopoIV must continually remove inter-DNA linkages during replication. There exists a short time lag of about 10–20 min between replication and segregation in which the daughter chromosomes are intertwined. Exactly where TopoIV binds during the cell cycle has been the subject of much debate. We show here that TopoIV localizes to the origin proximal side of the fork trailing protein SeqA and follows the movement pattern of the replication machinery in the cell.

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Section: Discussionmentioning

confidence: 99%

Topoisomerase IV tracks behind the replication fork and the SeqA complex during DNA replication in Escherichia coli

Helgesen

Sætre

Skarstad

2021

Sci Rep

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“…Saturated cultures of strains CL109, CL113, and CL281 were diluted to an optical density at 600 nm (OD 600 ) of 0.01 and grown at either 37°C (when CL109 and CL113 were compared) or 30°C (when CL109 and CL281 were compared) in M9 minimal medium supplemented with 20 g/ml each of thiamine, thymine, and uracil and either 0.2% glucose (for the comparison of CL109 and CL113) or 0.2% glycerol (for the comparison of CL109 and CL281) to an OD 600 of 0.1. Cells were viewed on grooved 4% agarose (NuSieve GTG; Lonza) pads prepared in 1ϫ phosphatebuffered saline (PBS) as described previously (57). Cells were imaged in the phase, Texas Red, and GFP channels in three consecutive 0.2-m Z-planes using a Nikon Eclipse Ti microscope with an Plan Apo 100ϫ/1.40-numerical-aperture objective and an Andor Neo CMOS camera enclosed in an Okolab environmental chamber held at the indicated temperatures.…”

Section: Methodsmentioning

confidence: 99%

Topoisomerase III Acts at the Replication Fork To Remove Precatenanes

et al. 2019

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The role of DNA topoisomerase III (Topo III) in bacterial cells has proven elusive. Whereas eukaryotic Top III␣ homologs are clearly involved with homologs of the bacterial DNA helicase RecQ in unraveling double Holliday junctions, preventing crossover exchange of genetic information at unscheduled recombination intermediates, and Top III␤ homologs have been shown to be involved in regulation of various mRNAs involved in neuronal function, there is little evidence for similar reactions in bacteria. Instead, most data point to Topo III playing a role supplemental to that of topoisomerase IV in unlinking daughter chromosomes during DNA replication. In support of this model, we show that Escherichia coli Topo III associates with the replication fork in vivo (likely via interactions with the single-stranded DNAbinding protein and the ␤ clamp-loading DnaX complex of the DNA polymerase III holoenzyme), that the DnaX complex stimulates the ability of Topo III to unlink both catenated and precatenated DNA rings, and that ΔtopB cells show delayed and disorganized nucleoid segregation compared to that of wild-type cells. These data argue that Topo III normally assists topoisomerase IV in chromosome decatenation by removing excess positive topological linkages at or near the replication fork as they are converted into precatenanes. IMPORTANCE Topological entanglement between daughter chromosomes has to be reduced to exactly zero every time an E. coli cell divides. The enzymatic agents that accomplish this task are the topoisomerases. E. coli possesses four topoisomerases. It has been thought that topoisomerase IV is primarily responsible for unlinking the daughter chromosomes during DNA replication. We show here that topoisomerase III also plays a role in this process and is specifically localized to the replisome, the multiprotein machine that duplicates the cell's genome, in order to do so.

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“…Besides its role in chromosome segregation, topoisomerase IV was also proposed to aid MukBEF complex in chromosome condensation. Recent data suggest that topoisomerase IV can stabilize the MukB homodimer on the DNA, and thus enhance compaction of DNA [ 105 ]. Interestingly, the same study shows that even catalytically inactive ParC subunit of topoisomerase IV is able to promote MukB driven compaction.…”

Section: Regulation Of Topoisomerase II Activity: Guidance By the mentioning

confidence: 99%

A Topology-Centric View on Mitotic Chromosome Architecture

Piskadlo

Oliveira

2017

IJMS

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Mitotic chromosomes are long-known structures, but their internal organization and the exact process by which they are assembled are still a great mystery in biology. Topoisomerase II is crucial for various aspects of mitotic chromosome organization. The unique ability of this enzyme to untangle topologically intertwined DNA molecules (catenations) is of utmost importance for the resolution of sister chromatid intertwines. Although still controversial, topoisomerase II has also been proposed to directly contribute to chromosome compaction, possibly by promoting chromosome self-entanglements. These two functions raise a strong directionality issue towards topoisomerase II reactions that are able to disentangle sister DNA molecules (in trans) while compacting the same DNA molecule (in cis). Here, we review the current knowledge on topoisomerase II role specifically during mitosis, and the mechanisms that directly or indirectly regulate its activity to ensure faithful chromosome segregation. In particular, we discuss how the activity or directionality of this enzyme could be regulated by the SMC (structural maintenance of chromosomes) complexes, predominantly cohesin and condensin, throughout mitosis.

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The MukB–topoisomerase IV interaction is required for proper chromosome compaction

Cited by 18 publications

References 45 publications

Topoisomerase IV tracks behind the replication fork and the SeqA complex during DNA replication in Escherichia coli

Topoisomerase IV tracks behind the replication fork and the SeqA complex during DNA replication in Escherichia coli

Topoisomerase III Acts at the Replication Fork To Remove Precatenanes

A Topology-Centric View on Mitotic Chromosome Architecture

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