Solution structure of the DNA-binding domain of interleukin enhancer binding factor 1 (FOXK1a).
Interleukin enhancer binding factor (ILF) binds to the interleukin-2 (IL-2) promoter and regulates IL-2 gene expression. In this study, the 3D structure of the DNA-binding domain of ILF was determined by multidimensional NMR spectroscopy. NMR structure analysis revealed that the DNA-binding domain of ILF is a new member of the winged helix/forkhead family, and that its wing 2 contains an extra alpha-helix. This is the first study to report the presence of a C-terminal alpha-helix in place of a typical wing 2 in a member of this family. This structural difference may be responsible for the different DNA-binding specificity of ILF compared to other winged helix/forkhead proteins. Our deletion studies of the fragments of ILF also suggest that the C-terminal region plays a regulatory role in DNA binding.
Liu
Pei-Phen
PP
Department of Biochemistry, National Cheng Kung University College of Medicine, Tainan 701, Taiwan.
Chen
Yen-Chin
YC
Li
Ching
C
Hsieh
Yu-Huei
YH
Chen
Shu-Wan
SW
Chen
Shu-Huei
SH
Jeng
Wen-Yih
WY
Chuang
Woei-Jer
WJ
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001483:Base Sequence; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D051858:Forkhead Transcription Factors; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012996:Solutions; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D004268:DNA-Binding Proteins; D051858:Forkhead Transcription Factors; D009687:Nuclear Proteins; D012996:Solutions; C070635:interleukin binding factor; D004247:DNA