title: Modulation of the relaxing activity of Escherichia coli topoisomerase I by single-stranded DNA binding proteins.
abstract: Removal of negative superhelical turns in ColE1 plasmid DNA by Escherichia coli topoisomerase I was markedly enhanced by the presence of single-stranded DNA binding protein from E. coli. A lack of species specificity makes unlikely the possibility of physical association between topoisomerase I and single-stranded DNA binding proteins. Stabilization of single-stranded regions in supercoiled DNA by single-stranded DNA binding protein would appear to be the basis of the enhancement of topoisomerase activity.
mesh_terms: D004264:DNA Topoisomerases, Type I / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004278:DNA, Superhelical / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D004926:Escherichia coli / Q000201:enzymology*; D010957:Plasmids
chemical_list: D004277:DNA, Single-Stranded; D004278:DNA, Superhelical; D004268:DNA-Binding Proteins; D004264:DNA Topoisomerases, Type I