Structural highlights
Function
[TTKB_DROME] Binds to a number of sites in the transcriptional regulatory region of ftz. Isoform beta is required to repress inappropriate segmentation gene transcription and repress genes incompatible with development of photoreceptor cell fates. Probable repressor of the transcription of the segmentation genes ftz, eve, h, odd, run, and en. Inhibits Trl-dependent activation of eve. May bind to the region AGGGC/TGG. Degradation of ttk is directed by binding of sinah or sina, via the adapter molecule phyl which binds to the BTB domain of ttk. A second method of degradation exists that is phyl-independent, this is mediated by recognition of motifs in the C-terminus of ttk.[1] [2] [3] [4] [5]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The Cys2-His2 zinc-finger is the most widely occurring DNA-binding motif. The first structure of a zinc-finger/DNA complex revealed a fairly simple mechanism for DNA recognition suggesting that the zinc-finger might represent a candidate template for designing proteins to recognize DNA. Residues at three key positions in an alpha-helical 'reading head' play a dominant role in base-recognition and have been targets for mutagenesis experiments aimed at deriving a recognition code. Here we report the structure of a two zinc-finger DNA-binding domain from the protein Tramtrack complexed with DNA. The amino-terminal zinc-finger and its interaction with DNA illustrate several novel features. These include the use of a serine residue, which is semi-conserved and located outside the three key positions, to make a base contact. Its role in base-recognition correlates with a large, local, protein-induced deformation of the DNA helix at a flexible A-T-A sequence and may give insight into previous mutagenesis experiments. It is apparent from this structure that zinc-finger/DNA recognition is more complex than was originally perceived.
The crystal structure of a two zinc-finger peptide reveals an extension to the rules for zinc-finger/DNA recognition.,Fairall L, Schwabe JW, Chapman L, Finch JT, Rhodes D Nature. 1993 Dec 2;366(6454):483-7. PMID:8247159[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Harrison SD, Travers AA. The tramtrack gene encodes a Drosophila finger protein that interacts with the ftz transcriptional regulatory region and shows a novel embryonic expression pattern. EMBO J. 1990 Jan;9(1):207-16. PMID:2104801
- ↑ Brown JL, Wu C. Repression of Drosophila pair-rule segmentation genes by ectopic expression of tramtrack. Development. 1993 Jan;117(1):45-58. PMID:8223261
- ↑ Xiong WC, Montell C. tramtrack is a transcriptional repressor required for cell fate determination in the Drosophila eye. Genes Dev. 1993 Jun;7(6):1085-96. PMID:8504931
- ↑ Pagans S, Ortiz-Lombardia M, Espinas ML, Bernues J, Azorin F. The Drosophila transcription factor tramtrack (TTK) interacts with Trithorax-like (GAGA) and represses GAGA-mediated activation. Nucleic Acids Res. 2002 Oct 15;30(20):4406-13. PMID:12384587
- ↑ Cooper SE, Murawsky CM, Lowe N, Travers AA. Two modes of degradation of the tramtrack transcription factors by Siah homologues. J Biol Chem. 2008 Jan 11;283(2):1076-83. Epub 2007 Oct 25. PMID:17962185 doi:http://dx.doi.org/10.1074/jbc.M707765200
- ↑ Fairall L, Schwabe JW, Chapman L, Finch JT, Rhodes D. The crystal structure of a two zinc-finger peptide reveals an extension to the rules for zinc-finger/DNA recognition. Nature. 1993 Dec 2;366(6454):483-7. PMID:8247159 doi:http://dx.doi.org/10.1038/366483a0
