title: Nucleic acid-binding glycoproteins which solubilize nucleic acids in dilute acid. Re-examination of the Ustilago maydis glycoproteins.
abstract: Holloman ((1975) J. Biol. Chem. 250, 2993-3000) reported the isolation from Ustilago maydis of a glycoprotein which prevented the precipitation of nucleic acids in cold 5% trichloroacetic acid. Two glycoprotein fractions from U. maydis with this nucleic acid-solubilizing activity were isolated in our laboratory using improved purification procedures. The activity was not due to nuclease contamination. The glycoproteins are distinguished by: their ability to bind to concanavalin A-Sepharose; their differential binding to double- and single-stranded deoxyribonucleic acid, and to ribonucleic acid; their molecular weights (46,000 and 69,000); and the relative amounts present in growing versus nongrowing cells. Both fractions required sulfhydryl-reducing conditions for optimal yields, specific activity, and stability. Nucleic acid binding was cooperative, the minimum number of glycoproteins required to make a native T7 DNA molecule soluble in dilute acid being estimated at 2 and 15, respectively.
mesh_terms: D001487:Basidiomycota / Q000378:metabolism*; D004279:DNA, Viral; D006023:Glycoproteins / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D012995:Solubility; D013604:T-Phages; D014588:Ustilago / Q000254:growth & development / Q000378:metabolism*
chemical_list: D004279:DNA, Viral; D006023:Glycoproteins