A novel activity of HMG domains: promotion of the triple-stranded complex formation between DNA containing (GGA/TCC)11 and d(GGA)11 oligonucleotides.
The high mobility group protein (HMG)-box is a DNA-binding domain found in many proteins that bind preferentially to DNA of irregular structures in a sequence-independent manner and can bend the DNA. We show here that GST-fusion proteins of HMG domains from HMG1 and HMG2 promote a triple-stranded complex formation between DNA containing the (GGA/TCC)11 repeat and oligonucleotides of d(GGA)11 probably due to G:G base pairing. The activity is to reduce association time and requirements of Mg2+ and oligonucleotide concentrations. The HMG box of SRY, the protein determining male-sex differentiation, also has the activity, suggesting that it is not restricted to the HMG-box domains derived from HMG1/2 but is common to those from other members of the HMG-box family of proteins. Interestingly, the box-AB and box-B of HMG1 bend DNA containing the repeat, but SRY fails to bend in a circularization assay. The difference suggests that the two activities of association-promotion and DNA bending are distinct. These results suggest that the HMG-box domain has a novel activity of promoting the association between GGA repeats which might be involved in higher-order architecture of chromatin.
Suda
T
T
First Department of Biochemistry, Niigata University School of Medicine, Japan.
Mishima
Y
Y
Takayanagi
K
K
Asakura
H
H
Odani
S
S
Kominami
R
R
D001482:Base Composition; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D003850:Deoxyribonuclease I; D004926:Escherichia coli / Q000235:genetics; D005982:Glutathione Transferase / Q000235:genetics; D006609:High Mobility Group Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology; D009687:Nuclear Proteins; D009841:Oligonucleotides / Q000737:chemistry* / Q000378:metabolism*; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D051876:Sex-Determining Region Y Protein; D014157:Transcription Factors
D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D009687:Nuclear Proteins; D009841:Oligonucleotides; D011993:Recombinant Fusion Proteins; D051876:Sex-Determining Region Y Protein; D014157:Transcription Factors; D004247:DNA; D005982:Glutathione Transferase; D003850:Deoxyribonuclease I; D008274:Magnesium