2C6Y: Crystal Structure Of Interleukin Enhancer-Binding Factor 1 Bound To Dna

Citation:
Abstract
Interleukin enhancer binding factor (ILF) is a human transcription factor and a new member of the winged helix/forkhead family. ILF can bind to purine-rich regulatory motifs such as the human T-cell leukemia virus-long terminal region and the interleukin-2 promoter. Here we report the 2.4 A crystal structure of two DNA binding domains of ILF (FOXK1a) binding to a 16-bp DNA duplex containing a promoter sequence. Electrophoretic mobility shift assay studies demonstrate that two ILF-DNA binding domain molecules cooperatively bind to DNA. In addition to the recognition helix recognizing the core sequences through the major groove, the structure shows that wing 1 interacts with the minor groove of DNA, and the H2-H3 loop region makes ionic bonds to the phosphate group, which permits the recognition of DNA. The structure also reveals that the presence of the C-terminal alpha-helix in place of a typical wing 2 in a member of this family alters the orientation of the C-terminal basic residues (RKRRPR) when binding to DNA outside the core sequence. These results provide a new insight into how the DNA binding specificities of winged helix/forkhead proteins may be regulated by their less conserved regions.
PDB ID: 2C6YDownload
MMDB ID: 86910
PDB Deposition Date: 2005/11/15
Updated in MMDB: 2010/12
Experimental Method:
x-ray diffraction
Resolution: 2.4  Å
Source Organism:
Similar Structures:
Biological Unit for 2C6Y: tetrameric; determined by author and by software (PQS)
Molecular Components in 2C6Y
Label Count Molecule
Proteins (2 molecules)
2
Forkhead BOX Protein K2(Gene symbol: FOXK2)
Molecule annotation
Nucleotides(2 molecules)
1
Interleukin 2 Promotor
Molecule annotation
1
Interleukin 2 Promotor
Molecule annotation
Chemicals (2 molecules)
1
2
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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