Multi-strand binding of nuclear factors to a repressor of mouse mammary tumor virus transcription can be distinguished kinetically

• Published in: Biochemical and biophysical research communications Vol. 209; no. 1; pp. 379 - 384
• Main Authors: Rodda, D J, Giffin, W, Haché, R J
• Format: Journal Article
• Language: English
• Published: United States 06-04-1995
• Subjects: Base Sequence; Cell Line; DNA, Single-Stranded - metabolism; DNA-Binding Proteins - metabolism; Humans; Kinetics; Mammary Tumor Virus, Mouse - genetics; Molecular Sequence Data; Nuclear Proteins - metabolism; Oligodeoxyribonucleotides; Protein Binding; Regulatory Sequences, Nucleic Acid; Repetitive Sequences, Nucleic Acid; Transcription, Genetic
• ISSN: 0006-291X

NRE1 is a DNA sequence element in the long terminal repeat of mouse mammary tumor virus that represses viral transcription in mature T cells. In addition to double-stranded binding activity, factors in Jurkat T cell nuclear extracts bind specifically to each of the two single-strands of NRE1. Here we show that binding to the three forms of NRE1 can be distinguished kinetically. The on rates for double, upper and lower-strand NRE1 binding were 1.5, 3, and 11 min, respectively. Binding was extremely stable with off-rates varying from 30 and 60 min for double and upper-strand binding to 12 h for lower-strand binding. In addition, a truncated form of NRE1 that is only bound as a double-strand was observed to have an on rate of binding of 4 min and an off rate of 4 h.