HOMEODOMAIN;
CIRCULAR DICHROISM;
TRANSCRIPTION FACTOR;
DNA BINDING;
PROTEIN STRUCTURE;
ALPHA-HELIX;
D O I:
10.1016/0014-5793(94)01145-1
中图分类号:
Q5 [生物化学];
Q7 [分子生物学];
学科分类号:
071010 ;
081704 ;
摘要:
The conformational stability of TTF-1HD has been determined by CD-monitored thermal denaturation and isothermal urea unfolding studies. The Gibbs free energy of stabilization found are 1.44 and 1.26 kcal.mol(-1), respectively. TTF-1HD exhibits a T-m of 42 degrees C and a Delta C-p of 80 cal.mol(-1) K-1 indicating that TTF-1HD, when free in solution, is a mobile flexible segment folded into loose helices. Such a flexibility would be relevant for the DNA-binding function of this homeodomain. In fact, a small reduction of the alpha-helical content of TTF-1HD significally modifies its DNA-binding activity.