A NOVEL ACTIVITY OF HMG DOMAINS - PROMOTION OF THE TRIPLE-STRANDED COMPLEX-FORMATION BETWEEN DNA CONTAINING (GGA TCC)(11) AND D(GGA)(11) OLIGONUCLEOTIDES/
T. Suda et al., A NOVEL ACTIVITY OF HMG DOMAINS - PROMOTION OF THE TRIPLE-STRANDED COMPLEX-FORMATION BETWEEN DNA CONTAINING (GGA TCC)(11) AND D(GGA)(11) OLIGONUCLEOTIDES/, Nucleic acids research, 24(23), 1996, pp. 4733-4740
The high mobility group protein (HMG)-box is a DNA-binding domain foun
d in many proteins that bind preferentially to DNA of irregular struct
ures in a sequence-independent manner and can bend the DNA, We show he
re that GST-fusion proteins of HMG domains from HMG1 and HMG2 promote
a triple-stranded complex formation between DNA containing the (GGA/TC
C)(11) repeat and oligonucleotides of d(GGA)(11) probably due to G:G b
ase pairing, The activity is to reduce association time and requiremen
ts 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 fr
om HMG1/2 but is common to those from other members of the HMG-box fam
ily of proteins, Interestingly, the box-AB and box-B of HMG1 bend DNA
containing the repeat, but SRY fails to bend in a circularization assa
y, The difference suggests that the two activities of association-prom
otion 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 ch
romatin.