2 edition of Purification and properties of a DNA topoisomerase I from Caulobacter crescentus found in the catalog.
Purification and properties of a DNA topoisomerase I from Caulobacter crescentus
Written in English
|Statement||by Li-Li Yang.|
|Contributions||Boston College. Dept. of Biology.|
|The Physical Object|
|Pagination||iv, 69 leaves,  leaves of plates :|
|Number of Pages||69|
DNA topoisomerases are enzymes that control the topology of DNA in all cells. There are two types, I and II, classified according to whether they make transient single- or double-stranded breaks in DNA. Their reactions generally involve the passage of a single- or double-strand segment of DNA through this transient break, stabilized by DNA-protein covalent bonds. Losasso C, Cretaio E, Fiorani P, D'Annessa I, Chillemi G, Benedetti P. Free in PMC A single mutation in the residue modulates human DNA topoisomerase IB DNA binding and drug resistance. Nucleic Acids Res. Oct;36(17)
Bacterial replication origins move towards opposite ends of the cell during DNA segregation. We have identified a proline-rich polar protein, PopZ, required to anchor the separated Caulobacter crescentus chromosome origins at the cell poles, a function that is essential for maintaining chromosome organization and normal cell division. A DNA occlusion mechanism would be particularly appropriate for C. crescentus, where the DNA fills virtually the entire cell except for the polar tips (Viollier et al., ). Consistent with a DNA occlusion mechanism, PopZ-YFP foci formed largely outside the DAPI-stained DNA in regions corresponding to the tip of the poles (Figure 6 I).
INTRODUCTION. Only two topoisomerases: topoisomerase I (type I topoisomerase) and gyrase (type II topoisomerase) are sufficient to maintain bacterial chromosome supercoiling ().Topoisomerase I homologs (named TopA or TopoI) belong to the type IA topoisomerases, which constitute a ubiquitous group of enzymes that remove an excess of negative supercoils using enzyme-bridged DNA strand . This chapter describes the molecular events that lead to the biogenesis of the Caulobacter crescentus flagellum and how these events are integrated into the generation of a new daughter cell type. Flagellar biogenesis is the best-known aspect of cellular differentiation in C. crescentus. The C. crescentus flagellum has been observed by electron microscopy and possesses a structure that is.
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SUMMARY Caulobacter crescentus is an aquatic Gram-negative alphaproteobacterium that undergoes multiple changes in cell shape, organelle production, subcellular distribution of proteins, and intracellular signaling throughout its life cycle. Over 40 years of research has been dedicated to this organism and its developmental life cycles.
Here we review a portion of many developmental Cited by: Regulation of the Caulobacter crescentus dnaKJ operon. J Bacteriol. Jun; (12)– [PMC free article] Benson AK, Ramakrishnan G, Ohta N, Feng J, Ninfa AJ, Newton A. The Caulobacter crescentus FlbD protein acts at ftr sequence elements both to activate and to repress transcription of cell cycle-regulated flagellar by: In Caulobacter crescentus the combined action of chromosome replication and the expression of DNA methyl-transferase CcrM at the end of S-phase maintains a cyclic alternation between a full- to.
On the other hand, several differences were found between the C. crescentus and E. coli RNA polymerases with respect to their interaction with Caulobacter phage phiCdl DNA.
In E. coli, ParC co-localized with the replication machinery, whereas ParE localized to DNA-free spaces in the cell (Espeli et al., a). In Caulobacter crescentus, ParC formed a sharp focus at. Topoisomerases, including gyrase and topoisomerase IV in bacteria, are required to relax positive supercoils ahead of DNA polymerase but may not be sufficient for replication.
Here, we find that GapR, a chromosome structuring protein in Caulobacter crescentus, is required to complete DNA. A DNA damage checkpoint in Caulobacter crescentus inhibits cell division through a direct interaction with FtsW. Genes Dev. 25, – [PMC free article] [Google Scholar] Postow L, Crisona NJ, Peter BJ, Hardy CD, and Cozzarelli NR ().
Topological challenges to DNA replication: conformations at the fork. Proc. Natl. Acad. Sci. C. crescentus is an ideal bacterial model system to examine chromosomal DNA partitioning since cell cycle–synchronized populations are easy to obtain and manipulate experimentally.
We show that purified ParB binds specifically to DNA sequences downstream of the parAB operon, which is located within 80 kbp of the origin of replication. Protein Purification. The coding regions of the M. tuberculosis GyrA CTD (–), full-length M.
tuberculosis gyrA (1–), and full-length gyrB (1–) were amplified from genomic DNA (ATCC) and cloned into a derivative of pET28b behind an N-terminal, tobacco etch virus protease-cleavable hexahistidine tag using an in-house ligation independent cloning vector system (pLIC).
Figure 1. S-phase-specific developmental regulators in C. crescentus.(A) Schematic showing the cell cycle abundance of the S-phase-specific regulatory molecules CcrM (brown) and GcrA (green) and the topo IV regulator NstA (negative switch for topo IV decatenation activity) (gray).Also shown are the replication and sequestration of the newly replicated origin (yellow) and the presence of ParC.
In Caulobacter crescentus, the genes encoding the chromosome partitioning proteins, ParA and ParB, are essential. Depletion of ParB resulted in smooth filamentous cells in which DNA replication. Background. The bacterium Caulobacter crescentus is a popular model for the study of cell cycle regulation and senescence.
The large prolate siphophage phiCbK has been an important tool in C. crescentus biology, and has been studied in its own right as a model for viral morphogenesis. Although a system of some interest, to date little genomic information is available on phiCbK or its relatives. In the bacterium C.
crescentus, the cellular homologs of plasmid partitioning proteins, ParA and ParB, localize to both poles of the predivisional cell following the completion of DNA replication. ParB binds to DNA sequences adjacent to the origin of replication suggesting that this region of the genome is tethered to the poles of the cell at a specific time in the cell cycle.
DNA topoisomerases are a diverse set of essential enzymes responsible for maintaining chromosomes in an appropriate topological state. Although they vary considerably in structure and mechanism, the partnership between topoisomerases and DNA has engendered commonalities in how these enzymes engage nucleic acid substrates and control DNA strand manipulations.
Purification, Characterization, and Reconstitution of DNA-dependent RNA Polymerases from Caulobacter crescentus Article (PDF Available) in Journal of Biological Chemistry (34) Morphogenesis in Caulobacter appears to be driven by internal cues, with stages of the cell division cycle acting as checkpoints for specific developmental events.
Genetic studies have identified signal transduction pathways mediated by members of the His-Asp phosphorelay proteins that are essential both for cell cycle control and developmental regulation.
Introduction. DNA topoisomerases are essential enzymes that help counteract the topological effects of nucleic acid transactions such as transcription, replication, and repair ().Nearly all bacteria, and some archaea, possess a unique topoisomerase, termed gyrase, which negatively supercoils DNA to maintain chromosomes in an underwound state (2, 3).
Swarmer cells of Caulobacter crescentus are devoid of the cell division initiation protein FtsZ and do not replicate DNA. FtsZ is synthesized during the differentiation of swarmer cells into replic. In Caulobacter crescentus, the response regulator CtrA fulfils a similar function.
Upon completion of DNA synthesis, the circular daughter chromosomes are separated through the action of topoisomerases and terminus‐specific recombinases, and then partitioned toward the poles of the pre‐divisional cell (reviewed in 42; 48).
Each Caulobacter crescentus cell division yields two distinct cell types: a flagellated swarmer cell and a non-motile stalked cell.
The swarmer cell is further distinguished from the stalked cell by an inability to reinitiate DNA replication, by the physical properties of its nucleoid, and its discrete program of gene expression. Hong SH, McAdams HH () Compaction and transport properties of newly replicated Caulobacter crescentus DNA.
Mol Microbiol – Wiley Online Library CAS PubMed Web of Science® Google Scholar; Hu P, Brodie EL, Suzuki Y, McAdams HH, Andersen GL () Whole‐genome transcriptional analysis of heavy metal stresses in Caulobacter.A Bacterial Chromosome Structuring Protein Binds Overtwisted DNA to Stimulate Type II Topoisomerases and Enable DNA Replication.
Guo M.S., Haakonsen D.L., Zeng W., Schumacher M.A., Laub M.T. () Cell, Epub ahead of print. Constriction Rate Modulation Can Drive Cell Size Control and Homeostasis in C. crescentus.Type II DNA methyltransferases (MTases) are enzymes found ubiquitously in the prokaryotic world, where they play important roles in several cellular processes, such as host protection and epigenetic regulation.
Three classes of type II MTases have been identified thus far in bacteria which function in transferring a methyl group from S -adenosyl-l-methionine (SAM) to a target nucleotide base.