title: Low-molecular- weight Rauscher leukemia virus protein with preferential binding for single-stranded RNA and DNA.
abstract: A sensitive nitrocellulose filter assay that measures the retention of 125I single-stranded calf thymus DNA has been used to detect and purify DNA-binding proteins that retain a biological function from Rauscher murine leukemia virus. By consecutive purification on oligo (dT)- cellulose and DEAE-Bio-Gel columns and centrifugation in 10 to 30% glycerol gradients, RNA-dependent DNA polymerase has been separated from a second virion DNA-binding protein. The binding of this protein to DNA was strongly affected by NaCl concentration but showed little change in activity over a wide range of temperature or pH. After glycerol gradient purification, polyacrylamide gel electrophoresis of this protein showed one major band with a molecular weight of approximately 9,800. This protein binds about as well as to single-stranded Escherichia coli or calf thymus DNA or 70S type C viral RNA. The binding to 125I single-stranded calf thymus DNA is very efficiently inhibited by unlabeled single-stranded DNA from either E. coli or calf thymus and by 70S murine or feline viral RNA. Much larger amounts of double-stranded DNA are required to produce an equivalent percentage of inhibition. This protein, therefore, shows preferential binding to single-stranded DNA or viral RNA.
mesh_terms: D000818:Animals; D002417:Cattle; D002460:Cell Line; D004269:DNA, Bacterial / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000378:metabolism; D004926:Escherichia coli; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D011485:Protein Binding; D012367:RNA, Viral / Q000378:metabolism; D012194:RNA-Directed DNA Polymerase / Q000302:isolation & purification / Q000378:metabolism; D011925:Rauscher Virus / Q000032:analysis* / Q000201:enzymology / Q000378:metabolism; D012190:Retroviridae; D012965:Sodium Chloride / Q000494:pharmacology; D013696:Temperature; D013950:Thymus Gland; D014764:Viral Proteins / Q000032:analysis* / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D012367:RNA, Viral; D014764:Viral Proteins; D012965:Sodium Chloride; D012194:RNA-Directed DNA Polymerase