2C6Y

Crystal structure of interleukin enhancer-binding factor 1 bound to DNA

Summary for 2C6Y

• Entry DOI: 10.2210/pdb2c6y/pdb
• Related: 1JXS
• Descriptor: FORKHEAD BOX PROTEIN K2, INTERLEUKIN 2 PROMOTOR, MAGNESIUM ION, ... (5 entities in total)
• Functional Keywords: transcription regulation, dna-binding domain, forkhead transcription factors, interleukin enhancer binding factor, winged helix, forkhead
• Biological source: HOMO SAPIENS (HUMAN); More
• Cellular location: Nucleus (Probable): Q01167
• Total number of polymer chains: 4
• Total formula weight: 35466.10

Authors

Tsai, K.-L.,Huang, C.-Y.,Chang, C.-H.,Sun, Y.-J.,Chuang, W.-J.,Hsiao, C.-D. (deposition date: 2005-11-15, release date: 2006-04-18, Last modification date: 2024-05-08)

Primary citation

Tsai, K.-L.,Huang, C.-Y.,Chang, C.-H.,Sun, Y.-J.,Chuang, W.-J.,Hsiao, C.-D.
Crystal Structure of the Human Foxk1A-DNA Complex and its Implications on the Diverse Binding Specificity of Winged Helix/Forkhead Proteins.
J.Biol.Chem., 281:17400-, 2006

PubMed 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.

PubMed: 16624804
DOI: 10.1074/JBC.M600478200

Experimental method

X-RAY DIFFRACTION (2.4 Å)