1WRT

NMR STUDY OF APO TRP REPRESSOR

Summary for 1WRT

• Entry DOI: 10.2210/pdb1wrt/pdb
• Descriptor: APO TRP REPRESSOR (1 entity in total)
• Functional Keywords: operon repressor, transcription regulation, dna-binding
• Biological source: Escherichia coli
• Cellular location: Cytoplasm: P0A881
• Total number of polymer chains: 2
• Total formula weight: 24079.45

Authors

Zhao, D.,Zheng, Z. (deposition date: 1995-05-12, release date: 1996-06-20, Last modification date: 2024-05-22)

Primary citation

Zhao, D.,Arrowsmith, C.H.,Jia, X.,Jardetzky, O.
Refined solution structures of the Escherichia coli trp holo- and aporepressor.
J.Mol.Biol., 229:735-746, 1993

PubMed Abstract: The solution structures of the trp-repressor from Escherichia coli in both the liganded (holo-) and unliganded (apo-) form, have been refined by restrained molecular dynamics with simulated annealing using the program XPLOR and additional experimental constraints. The ensemble of refined holorepressor structures have a root-mean-square deviation (r.m.s.d.) of 0.8 A relative to the average structure for the backbone of the dimer core (helices A, B, C, A', B', C') and 2.5 A for the helix-turn-helix DNA-binding domain (helices D and E). The corresponding values for the aporepressor are 0.9 A for the backbone of the ABC-dimer core and 3.2 A for the DE helix-turn-helix. The r.m.s.d. of the average structures from the corresponding crystal structures are 2.3 A for the holorepressor ABC core and 4.2 A for its DE region; 2.3 A for the aporepressor core and 5.5 A for its DE region. The relative disorder of the DNA-binding domain is reflected in a number of experimental parameters including substantially more rapid backbone proton exchange rates, exchange-limited relaxation times and crystallographic B-factors. The stabilizing effect of the L-Trp ligand is evident in these measurements, as it is in the higher precision of the holorepressor structure.

PubMed: 8433368
DOI: 10.1006/jmbi.1993.1076

Experimental method

SOLUTION NMR