2xgd | pdb_00002xgd

Crystal structure of a designed homodimeric variant T-A(L)A(L) of the tetracycline repressor

spinqualitylabelsall models 2xgd, resolution 2.25Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2xgd is a 1 chain structure with sequence from "bacillus_coli"_migula_1895 "bacillus coli" migula 1895. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: CL Related: 1a6i, 2x6o, 1qpi, 1bjz, 2x9d, 2vke, 1du7, 2trt, 2vkv, 2xb5, 1ork, 1bj0, 1bjy, 2tct, 2xgc, 2xge Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [TETR2_ECOLX] TetR is the repressor of the tetracycline resistance element; its N-terminal region forms a helix-turn-helix structure and binds DNA. Binding of tetracycline to TetR reduces the repressor affinity for the tetracycline resistance gene (tetA) promoter operator sites. 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 specificity and selectivity of protein-protein interactions are of central importance for many biological processes, including signal transduction and transcription control. We used the in-house side-chain packing program MUMBO to computationally design a chain-specific heterodimeric variant of the bacterial transcription regulator tetracycline repressor (TetR), called T-A(A)B. Our goal was to engineer two different TetR chain variants, A and B, that no longer interact as AA or BB homodimers but selectively recombine to form heterodimers. Although 56 residues from each chain contribute to a dimer interface as large as 2200 A(2) in wild-type TetR, the substitution of only three residues in one chain and two residues in a second chain sufficed for generating specificity in a T-A(A)B heterodimer variant. The design was corroborated in vivo by a cell-based transcription assay, and in vitro by CD spectroscopy and X-ray crystallography. Crystal structure analyses showed that while selectivity in the B chain is achieved entirely through van der Waals repulsion, the best selectivity in the A chain is obtained for the variant with the lowest number of atoms in the interface, thus possibly leading to underpacking of the dimer interface. This results in a marked decrease in thermal stability and a drastic reduction in the solubility of the T-A(A)A(A) homodimer in comparison to the designed T-A(A)B heterodimer variant. Computational Design of a Chain-Specific Tetracycline Repressor Heterodimer.,Stiebritz MT, Wengrzik S, Klein DL, Richter JP, Srebrzynski A, Weiler S, Muller YA J Mol Biol. 2010 Sep 10. PMID:20816982 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Tetracycline repressor protein 3D structures

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