scholarly journals Control of Initiation of Sporulation by Replication Initiation Genes in Bacillus subtilis

2000 ◽  
Vol 182 (10) ◽  
pp. 2989-2991 ◽  
Author(s):  
Katherine P. Lemon ◽  
Iren Kurtser ◽  
Judy Wu ◽  
Alan D. Grossman

ABSTRACT Initiation of spore formation in Bacillus subtilisappears to depend on initiation of DNA replication. This regulation was first identified using a temperature-sensitive mutation indnaB. We found that mutations in the replication initiation genes dnaA and dnaD also inhibit sporulation, indicating that inhibition of sporulation is triggered by general defects in the function of replication initiation proteins.

2019 ◽  
Vol 16 (3) ◽  
pp. 272-277 ◽  
Author(s):  
Rasmus N. Klitgaard ◽  
Anders Løbner-Olesen

Background:One of many strategies to overcome antibiotic resistance is the discovery of compounds targeting cellular processes, which have not yet been exploited.Materials and Methods:Using various genetic tools, we constructed a novel high throughput, cellbased, fluorescence screen for inhibitors of chromosome replication initiation in bacteria.Results:The screen was validated by expression of an intra-cellular cyclic peptide interfering with the initiator protein DnaA and by over-expression of the negative initiation regulator SeqA. We also demonstrated that neither tetracycline nor ciprofloxacin triggers a false positive result. Finally, 400 extracts isolated mainly from filamentous actinomycetes were subjected to the screen.Conclusion:We concluded that the presented screen is applicable for identifying putative inhibitors of DNA replication initiation in a high throughput setup.


2010 ◽  
Vol 192 (13) ◽  
pp. 3452-3463 ◽  
Author(s):  
Nicole M. Dupes ◽  
Brian W. Walsh ◽  
Andrew D. Klocko ◽  
Justin S. Lenhart ◽  
Heather L. Peterson ◽  
...  

ABSTRACT The β clamp is an essential replication sliding clamp required for processive DNA synthesis. The β clamp is also critical for several additional aspects of DNA metabolism, including DNA mismatch repair (MMR). The dnaN5 allele of Bacillus subtilis encodes a mutant form of β clamp containing the G73R substitution. Cells with the dnaN5 allele are temperature sensitive for growth due to a defect in DNA replication at 49°C, and they show an increase in mutation frequency caused by a partial defect in MMR at permissive temperatures. We selected for intragenic suppressors of dnaN5 that rescued viability at 49°C to determine if the DNA replication defect could be separated from the MMR defect. We isolated three intragenic suppressors of dnaN5 that restored growth at the nonpermissive temperature while maintaining an increase in mutation frequency. All three dnaN alleles encoded the G73R substitution along with one of three novel missense mutations. The missense mutations isolated were S22P, S181G, and E346K. Of these, S181G and E346K are located near the hydrophobic cleft of the β clamp, a common site occupied by proteins that bind the β clamp. Using several methods, we show that the increase in mutation frequency resulting from each dnaN allele is linked to a defect in MMR. Moreover, we found that S181G and E346K allowed growth at elevated temperatures and did not have an appreciable effect on mutation frequency when separated from G73R. Thus, we found that specific residue changes in the B. subtilis β clamp separate the role of the β clamp in DNA replication from its role in MMR.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Katarzyna Wegrzyn ◽  
Igor Konieczny

Abstract Objective The ability to form nucleoprotein complexes is a fundamental activity of DNA replication initiation proteins. They bind within or nearby the region of replication origin what results in melting of a double-stranded DNA (dsDNA) and formation of single-stranded DNA (ssDNA) region where the replication machinery can assemble. For prokaryotic initiators it was shown that they interact with the formed ssDNA and that this interaction is required for the replication activity. The ability to interact with ssDNA was also shown for Saccharomyces cerevisiae replication initiation protein complex ORC. For Archaea, which combine features of both prokaryotic and eukaryotic organisms, there was no evidence whether DNA replication initiators can interact with ssDNA. We address this issue in this study. Results Using purified Orc1 protein from Aeropyrum pernix (ApOrc1) we analyzed its ability to interact with ssDNA containing sequence of an AT-rich region of the A. pernix origin Ori1 as well as with homopolymers of thymidine (polyT) and adenosine (polyA). The Bio-layer interferometry, surface plasmon resonance and microscale thermophoresis showed that the ApOrc1 can interact with ssDNA and it binds preferentially to T-rich ssDNA. The hydrolysis of ATP is not required for this interaction.


2001 ◽  
Vol 183 (18) ◽  
pp. 5459-5464 ◽  
Author(s):  
Beatrice Grabowski ◽  
Zvi Kelman

ABSTRACT The initiator protein Cdc6 (Cdc18 in fission yeast) plays an essential role in the initiation of eukaryotic DNA replication. In yeast the protein is expressed before initiation of DNA replication and is thought to be essential for loading of the helicase onto origin DNA. The biochemical properties of the protein, however, are largely unknown. Using three archaeal homologues of Cdc6, it was found that the proteins are autophosphorylated on Ser residues. The winged-helix domain at the C terminus of Cdc6 interacts with DNA, which apparently regulates the autophosphorylation reaction. Yeast Cdc18 was also found to autophosphorylate, suggesting that this function of Cdc6 may play a widely conserved and essential role in replication initiation.


Cell Cycle ◽  
2019 ◽  
Vol 18 (6-7) ◽  
pp. 723-741 ◽  
Author(s):  
Rentian Wu ◽  
Aftab Amin ◽  
Ziyi Wang ◽  
Yining Huang ◽  
Marco Man-Hei Cheung ◽  
...  

2010 ◽  
Vol 192 (15) ◽  
pp. 3893-3902 ◽  
Author(s):  
Antonio A. Iniesta ◽  
Nathan J. Hillson ◽  
Lucy Shapiro

ABSTRACT Caulobacter crescentus initiates a single round of DNA replication during each cell cycle. Following the initiation of DNA replication, the essential CckA histidine kinase is activated by phosphorylation, which (via the ChpT phosphotransferase) enables the phosphorylation and activation of the CtrA global regulator. CtrA∼P then blocks the reinitiation of replication while regulating the transcription of a large number of cell cycle-controlled genes. It has been shown that DNA replication serves as a checkpoint for flagellar biosynthesis and cell division and that this checkpoint is mediated by the availability of active CtrA. Because CckA∼P promotes the activation of CtrA, we addressed the question of what controls the temporal activation of CckA. We found that the initiation of DNA replication is a prerequisite for remodeling the new cell pole, which includes the localization of the DivL protein kinase to that pole and, consequently, the localization, autophosphorylation, and activation of CckA at that pole. Thus, CckA activation is dependent on polar remodeling and a DNA replication initiation checkpoint that is tightly integrated with the polar phospho-signaling cascade governing cell cycle progression.


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