title: A DNA-binding protein from Ustilago maydis prefers duplex DNA without chain interruptions.
abstract: Using a nitrocellulose filter binding assay, we have partially purified a protein from mitotic cells of Ustilago maydis that binds preferentially to covalently closed circular duplex DNA. DNA containing single- or double-strand breaks is bound poorly by the protein. Once formed, the DNA-protein complex is stable, resisting dissociation in high salt. However, when a DNA strand is broken, the complex appears to dissociate. The protein binds equally well to form I DNA of phi X174 or the plasmid pBR322, but has a higher affinity for a hybrid plasmid containing a cloned region of Drosophila melanogaster satellite DNA.
mesh_terms: D001665:Binding Sites; D004265:DNA Helicases / Q000378:metabolism*; D004276:DNA, Satellite / Q000378:metabolism*; D004268:DNA-Binding Proteins; D005658:Fungi; D011485:Protein Binding; D013329:Structure-Activity Relationship
chemical_list: D004276:DNA, Satellite; D004268:DNA-Binding Proteins; D004265:DNA Helicases