Comparative Study of the Coupling between Topoisomerase I Activity and High-Mobility Group Proteins in E. coli and Mammalian Cells

Veilleux, St�phane; Caron, Nicolas; Boissonneault, Guylain
July 2000
DNA & Cell Biology;Jul2000, Vol. 19 Issue 7, p421
Academic Journal
It is now well established that the HMG box DNA-binding motif can alter the topology of double-stranded DNA in several ways. Using the spermatid-specific tsHMG as a model protein of the HMG-1/-2 family, we have demonstrated that its expression in E. coli produces an increase in plasmid supercoiling density that is likely a consequence of its ability to constrain free supercoils in vivo. As demonstrated in vitro, stabilization of free DNA supercoils by tsHMG prevents topoisomerase I from gaining access to the template and could represent a mechanism for the apparent inhibition of topoisomerase I in bacteria. A similar modulation of eukaryotic topoisomerase I activity was not detected after expression of the tsHMG in mammalian cells. This differential response is discussed in terms of the marked difference in DNA packaging and accessibility of free supercoils in prokaryotic vs. eukaryotic cells.


Related Articles

  • Three-dimensional structure of the 67k N-terminal fragment of E. coli DNA topoisomerase I. Lima, Christopher D.; Wang, James C. // Nature;1/13/1994, Vol. 367 Issue 6459, p138 

    Presents the crystal structure of the 67K amino-terminal fragment of Escherichia (E.) coli DNA topoisomerase I to a resolution of 2.2 angstroms. Multiple isomorphous replacement (MIR) phasing using three heavy-atom derivatives; Folding of the four distinct domains; Dimensions of the generated...

  • Structure of the multisubunit complex that promotes DNA branch migration. Parsons, Carol A.; Stasiak, Adrzej // Nature;3/23/1995, Vol. 374 Issue 6520, p375 

    Studies the mechanism in which RuvA and RuvB proteins of Escherichia coli bacterium promotes DNA branch migration. Formation of a tripartite protein complex; Characteristics of the Holliday junction within the complex; Creation of molecular model for DNA branch migration.

  • Computer Analysis of Conformational and Physicochemical Properties of Nucleotide Sequences Cleavable by DNA Topoisomerase I. Oshchepkov, D. Yu.; Bugreev, D. V.; Kolchanov, N. A.; Nevinsky, G. A. // Molecular Biology;May2005, Vol. 39 Issue 3, p430 

    DNA binding with enzymes is followed by specific adaptation of the DNA structure, including partial or almost complete melting, structural changes in the sugar-phosphate backbone, stretching, compressing, bending or kinking, base flipping, etc. The set of conformational changes is individual for...

  • Topoisomerase I regulates open chromatin and controls gene expression in vivo. Durand-Dubief, Mickaël; Persson, Jenna; Norman, Ulrika; Hartsuiker, Edgar; Ekwall, Karl // EMBO Journal;7/7/2010, Vol. 29 Issue 13, p2126 

    DNA topoisomerases regulate the topological state of the DNA double helix and are key enzymes in the processes of DNA replication, transcription and genome stability. Using the fission yeast model Schizosaccharomyces pombe, we investigate genome wide how DNA topoisomerases I and II affect...

  • Why eukaryotic cells use introns to enhance gene expression: Splicing reduces transcriptionassociated mutagenesis by inhibiting topoisomerase I cutting activity.  // Biology Direct;2011, Vol. 6 Issue 1, p24 

    The article offers information on the use of spliceosomal introns by eukaryotic cells to improve gene expression. It states that every step of gene expression, from transcription to translation is enhanced by introns and their splicing. It also states that intron-containing genes produce more...

  • Topoisomerase I function during Escherichia coli response to antibiotics and stress enhances cell killing from stabilization of its cleavage complex. I-Fen Liu; Sutherland, Jeanette H.; Bokun Cheng; Yuk-Ching Tse-Dinh // Journal of Antimicrobial Chemotherapy (JAC);Jul2011, Vol. 66 Issue 7, p1518 

    Objectives To explore the role of topoisomerase I in gene activation and increased RecA levels during the bacterial SOS response, as well as the effect of antibiotic treatment and stress challenge on cell killing initiated by trapped topoisomerase I cleavage complex. Methods A mutant Escherichia...

  • Bacterial chromosomes: IPOD maps occupied territory. Jermy, Andrew // Nature Reviews Microbiology;Oct2009, Vol. 7 Issue 10, p690 

    The article focuses on the development of a technology called in vivo protein occupancy display (IPOD). It references the study "Protein occupancy landscape of a bacterial genome.," by T. Vora and colleagues in the 2009 issue of "Molecular Cell." It mentions that IPOD is structured for a...

  • Combining Quantitative Genetic Footprinting and Trait Enrichment Analysis to Identify Fitness Determinants of a Bacterial Pathogen. Wiles, Travis J.; Norton, J. Paul; Russell, Colin W.; Dalley, Brian K.; Fischer, Kael F.; Mulvey, Matthew A. // PLoS Genetics;Aug2013, Vol. 9 Issue 8, p1 

    Strains of Extraintestinal Pathogenic Escherichiacoli (ExPEC) exhibit an array of virulence strategies and are a major cause of urinary tract infections, sepsis and meningitis. Efforts to understand ExPEC pathogenesis are challenged by the high degree of genetic and phenotypic variation that...

  • To bind or not to bind. Biggin, Mark D. // Nature Genetics;Aug2001, Vol. 28 Issue 4, p303 

    Examines the extent to which protein-DNA interactions are influenced by the intrinsic sequence-specific recognition properties at each protein. Regulation of gene expression by transcription factors binding selectively to particular portions of the genome; Results of genomewide surveys of DNA...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics