title: Path of DNA within the Mu transpososome. Transposase interactions bridging two Mu ends and the enhancer trap five DNA supercoils.
abstract: The phage Mu transpososome is assembled by interactions of transposase subunits with the left (L) and right (R) ends of Mu and an enhancer (E) located in between. A metastable three-site complex LER progresses into a more stable type 0 complex in which a tetrameric transposase is poised for DNA cleavage. "Difference topology" has revealed five trapped negative supercoils within type 0, three contributed by crossings of E with L and R, and two by crossings of L with R. This is the most complex DNA arrangement seen to date within a recombination synapse. Contrary to the prevailing notion, the enhancer appears not to be released immediately following type 0 assembly. Difference topology provides a simple method for determining the ordered sequestration of DNA segments within nucleoprotein assemblies.
authors.affiliation: Section of Molecular Genetics and Microbiology and Institute of Cellular and Molecular Biology, University of Texas at Austin, 78712, USA.
authors.forename: Shailja
authors.initials: S
authors.lastname: Pathania
authors.forename: Makkuni
authors.initials: M
authors.lastname: Jayaram
authors.forename: Rasika M
authors.initials: RM
authors.lastname: Harshey
mesh_terms: D010583:Bacteriophage mu / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D001681:Biological Assay; D004251:DNA Transposable Elements / Q000235:genetics*; D004278:DNA, Superhelical / Q000235:genetics* / Q000378:metabolism; D004279:DNA, Viral / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D015967:Gene Expression Regulation, Viral / Q000235:genetics; D019426:Integrases / Q000235:genetics / Q000378:metabolism; D015394:Molecular Structure; D010957:Plasmids / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics; D019895:Transposases / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D004251:DNA Transposable Elements; D004278:DNA, Superhelical; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D014764:Viral Proteins; C045073:Cre recombinase; D019426:Integrases; D019895:Transposases