Binding of human mitochondrial transcription factor A, an HMG box protein, to a four-way DNA junction.
Mitochondrial transcription factor A (mtTFA), the only known transcription factor in mitochondria, is also implicated in maintenance of mitochondrial genome although little is elucidated about its molecular basis. mtTFA is a member of HMG box proteins family. Some HMG proteins bind with high affinity to four-way DNA junctions that mimic a Holliday structure, a putative intermediate in DNA recombination. To explore possible involvement of a Holliday-like structure in the maintenance of mitochondrial genome, we examine the binding of recombinant human mtTFA to a synthetic four-way DNA junction. The human mtTFA binds to the four-way DNA junction with an approximately 10-fold higher affinity than to the corresponding linear duplex DNA and with essentially the same affinity as to a 40-mer DNA containing the human mitochondrial light strand promoter sequence. The mtTFA binds to the four-way as a monomer. Both of the two HMG box domains of human mtTFA are required for the high affinity binding to the four-way junction.
Ohno
T
T
Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan.
Umeda
S
S
Hamasaki
N
N
Kang
D
D
D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015723:Gene Library; D005982:Glutathione Transferase / Q000378:metabolism; D006367:HeLa Cells; D006609:High Mobility Group Proteins / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010957:Plasmids; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D020349:Surface Plasmon Resonance; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism*; D029867:Xenopus Proteins
D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D011994:Recombinant Proteins; D015534:Trans-Activators; C097078:XL-MTTFA protein, Xenopus; D029867:Xenopus Proteins; D005982:Glutathione Transferase; D008274:Magnesium