Send to

Choose Destination
Nucleic Acids Res. 1996 Mar 15;24(6):1047-51.

The DNA bend angle and binding affinity of an HMG box increased by the presence of short terminal arms.

Author information

Biophysics Laboratories, University of Portsmouth, United Kingdom.


The HMG box of human LEF-1 (hLEF-1, formerly TCF1alpha) has been expressed in four forms: a parent box of 81 amino acids and constructs having either a 10 amino acid C-terminal extension, a 9 amino acid N-terminal extension, or both. These four species have been compared for DNA binding and bending ability using a 28 bp recognition sequence from the TCR alpha-chain enhancer. In the bending assay, whereas the parent box and that with the N-terminal extension bent the DNA by 57/58 degrees, the box extended at the C-terminus bent the DNA by 77/78 degrees, irrespective of the presence or absence of the N-terminal extension. A 6- fold increase in DNA affinity also resulted from addition of both terminal extensions. These observations redefine the functional boundaries of the HMG box. The structure of a mouse LEF-1/DNA complex recently published [Love et al. (1995) Nature 376, 791-795] implies that the higher DNA affinity and in particular the increased bend angle observed are consequences, at least in part, of the C-terminal extension spanning the major groove on the inside of the DNA bend.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center