2ebi

Arabidopsis GT-1 DNA-binding domain with T133D phosphomimetic mutation

spinqualitylabelsall models 2ebi, 20 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2ebi is a 1 chain structure with sequence from Arath. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 2jmw Gene: T6J4.18 (ARATH) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Function [TGT1_ARATH] Probable transcription factor that binds specifically to the core DNA sequence 5'-GGTTAA-3'. May act as a molecular switch in response to light signals. 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 GT-1 is a plant transcription factor that binds to one of the cis-acting elements, BoxII, which resides within the upstream promoter region of light-responsive genes. GT-1 was assumed to act as a molecular switch modulated through Ca(2+)-dependent phosphorylation/dephosphorylation in response to light signals. It was shown previously that the phosphorylation of threonine 133 in the DNA-binding domain (DBD) of GT-1 results in enhancement of the BoxII-binding activity. Interestingly, point mutation of Thr133 to Asp also enhances the BoxII-binding activity. Here, we report the solution structures of hypothetical trihelix DBDs of the wild-type (WT) and a phosphomimetic mutant (T133D) of GT-1. First, we demonstrated that the isolated DBD of GT-1 alone has the ability to bind to DNA, and that the T133D mutation of the isolated DBD can enhance the DNA-binding affinity. The structures of these DBDs turned out to be almost identical. The structural topology resembles that of Myb DBDs, but all alpha-helices are longer in GT-1. Our NMR titration experiments suggested that these longer alpha-helices yield an enlarged DNA-binding surface. The phosphorylation site is located at the N-terminus of the third alpha-helix. We built a structural model of the T133D DBD:BoxII complex with the program HADDOCK. The model resembles the structure of the TRF1 DBD:telomeric DNA complex. Interestingly, the model implies that the phosphorylated side chain may directly interact with the bases of DNA. On the basis of our findings, we propose a mechanism by which the DNA-binding activity toward BoxII of the phosphorylated GT-1 could be enhanced. Solution structures of the trihelix DNA-binding domains of the wild-type and a phosphomimetic mutant of Arabidopsis GT-1: mechanism for an increase in DNA-binding affinity through phosphorylation.,Nagata T, Niyada E, Fujimoto N, Nagasaki Y, Noto K, Miyanoiri Y, Murata J, Hiratsuka K, Katahira M Proteins. 2010 Nov 1;78(14):3033-47. PMID:20717979 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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