2XDI
Tryptophan repressor with L75F mutation in its apo form (no L- tryptophan bound)
Summary for 2XDI
| Entry DOI | 10.2210/pdb2xdi/pdb |
| Descriptor | TRP OPERON REPRESSOR (1 entity in total) |
| Functional Keywords | apo-l75f-trpr, l-trp binding, transcription |
| Biological source | ESCHERICHIA COLI |
| Cellular location | Cytoplasm (By similarity): P0A882 |
| Total number of polymer chains | 2 |
| Total formula weight | 24545.90 |
| Authors | |
| Primary citation | Tyler, R.,Pelczer, I.,Carey, J.,Copie, V. Three-Dimensional Solution NMR Structure of Apo-L75F-Trpr, a Temperature-Sensitive Mutant of the Tryptophan Repressor Protein. Biochemistry, 41:11954-, 2002 Cited by PubMed Abstract: L75F-TrpR is a temperature-sensitive mutant of the tryptophan repressor protein of Escherichia coli in which surface-exposed residue leucine 75 in the DNA binding domain is replaced with phenylalanine. Biochemical and biophysical studies had suggested global alterations in dynamics for L75F-TrpR, although the structure was apparently similar to that of wild-type TrpR. Herein, we report the three-dimensional solution structure of apo-L75F-TrpR determined by multidimensional ((1)H, (15)N, and (13)C) solution NMR spectroscopy. An ensemble of structures was generated from 769 unique NOE-based distance restraints, 68 dihedral angle restraints, and 62 hydrogen bond distance restraints. Apo-L75F-TrpR exhibits a three-dimensional (3D) fold very similar to that of apo-WT-TrpR, with a dimeric core of four alpha-helices (A-C and F) from each subunit, and less well-defined D and E helical regions of the DNA binding domains. Despite their many similarities, wild-type and mutant proteins display significant chemical shift differences, one cluster of which is in the B-C turn, too distant to be ascribed solely to ring current effects from Phe75. Differences in NOE patterns and amide proton exchange rates are also observed in the B-C turn region. The data provide evidence that this point mutation exerts local effects on structure and stability in the DNA binding domain, and propagates long-range effects through the tertiary structure. PubMed: 12356295DOI: 10.1021/BI020304T PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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