1hbw

Solution nmr structure of the dimerization domain of the yeast transcriptional activator Gal4 (residues 50-106)

spinqualitylabelsall models 1hbw Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1hbw is a 2 chain structure with sequence from Saccharomyces cerevisiae. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GAL4_YEAST This protein is a positive regulator for the gene expression of the galactose-induced genes such as GAL1, GAL2, GAL7, GAL10, and MEL1 which code for the enzymes used to convert galactose to glucose. It recognizes a 17 base pair sequence in (5'-CGGRNNRCYNYNCNCCG-3') the upstream activating sequence (UAS-G) of these genes. Publication Abstract from PubMed The GAL4 dimerization domain (GAL4-dd) is a powerful transcriptional activator when tethered to DNA in a cell bearing a mutant of the GAL11 protein, named GAL11P. GAL11P (like GAL11) is a component of the RNA-polymerase II holoenzyme. Nuclear magnetic resonance (NMR) studies of GAL4-dd revealed an elongated dimer structure with C(2) symmetry containing three helices that mediate dimerization via coiled-coil contacts. The two loops between the three coiled coils form mobile bulges causing a variation of twist angles between the helix pairs. Chemical shift perturbation analysis mapped the GAL11P-binding site to the C-terminal helix alpha3 and the loop between alpha1 and alpha2. One GAL11P monomer binds to one GAL4-dd dimer rendering the dimer asymmetric and implying an extreme negative cooperativity mechanism. Alanine-scanning mutagenesis of GAL4-dd showed that the NMR-derived GAL11P-binding face is crucial for the novel transcriptional activating function of the GAL4-dd on GAL11P interaction. The binding of GAL4 to GAL11P, although an artificial interaction, represents a unique structural motif for an activating region capable of binding to a single target to effect gene expression. Recruitment of the transcriptional machinery through GAL11P: structure and interactions of the GAL4 dimerization domain.,Hidalgo P, Ansari AZ, Schmidt P, Hare B, Simkovich N, Farrell S, Shin EJ, Ptashne M, Wagner G Genes Dev. 2001 Apr 15;15(8):1007-20. PMID:11316794 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Gal3-Gal80-Gal4

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