1hbw
From Proteopedia
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SOLUTION NMR STRUCTURE OF THE DIMERIZATION DOMAIN OF THE YEAST TRANSCRIPTIONAL ACTIVATOR GAL4 (RESIDUES 50-106)
Overview
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.
About this Structure
1HBW is a Single protein structure of sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
Reference
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
Page seeded by OCA on Thu Feb 21 12:59:38 2008
