Identification of homologous pairing and strand-exchange activity from a human tumor cell line based on Z-DNA affinity chromatography.
An enzymatic activity that catalyzes ATP-dependent homologous pairing and strand exchange of duplex linear DNA and single-stranded circular DNA has been purified several thousand-fold from a human leukemic T-lymphoblast cell line. The activity was identified after chromatography of nuclear proteins on a Z-DNA column matrix. The reaction was shown to transfer the complementary single strand from a donor duplex linear substrate to a viral circular single-stranded acceptor beginning at the 5' end and proceeding in the 3' direction (5'----3'). Products of the strand-transfer reaction were characterized by electron microscopy. A 74-kDa protein was identified as the major ATP-binding peptide in active strand transferase fractions. The protein preparation described in this report binds more strongly to Z-DNA than to B-DNA.
D000251:Adenosine Triphosphatases / Q000302:isolation & purification / Q000378:metabolism; D002460:Cell Line; D002846:Chromatography, Affinity; D004247:DNA / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D003851:Deoxyribonucleases / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D007945:Leukemia, Lymphoid; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D011089:Polydeoxyribonucleotides
D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D011089:Polydeoxyribonucleotides; D004247:DNA; D003851:Deoxyribonucleases; D000251:Adenosine Triphosphatases