2oz9

E. coli TRP holorepressor, orthorhombic crystal form

spinqualitylabelsall models 2oz9, resolution 1.65Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2oz9 is a 1 chain structure with sequence from Escherichia coli. This structure supersedes the now removed PDB entry 2wrp. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: NA, SO4, TRP Related: 1wrp Gene: trpR, rtrY (Escherichia coli) Resources: FirstGlance, OCA, RCSB, PDBsum Function [TRPR_ECOLI] This protein is an aporepressor. When complexed with L-tryptophan it binds the operator region of the trp operon (5'-ACTAGT-'3') and prevents the initiation of transcription. The complex also regulates trp repressor biosynthesis by binding to its regulatory region. 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 An orthorhombic crystal form of trp repressor (aporepressor plus L-tryptophan ligand) was solved by molecular replacement, refined to 1.65 A resolution, and compared to the structure of the repressor in trigonal crystals. Even though these two crystal forms of repressor were grown under identical conditions, the refined structures have distinctly different conformations of the DNA-binding domains. Unlike the repressor/aporepressor structural transition, the conformational shift is not caused by the binding or loss of the L-tryptophan ligand. We conclude that while L-tryptophan binding is essential for forming a specific complex with trp operator DNA, the corepressor ligand does not lock the repressor into a single conformation that is complementary to the operator. This flexibility may be required by the various binding modes proposed for trp repressor in its search for and adherence to its three different operator sites. Flexibility of the DNA-binding domains of trp repressor.,Lawson CL, Zhang RG, Schevitz RW, Otwinowski Z, Joachimiak A, Sigler PB Proteins. 1988;3(1):18-31. PMID:3375234 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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