1EFA

CRYSTAL STRUCTURE OF THE LAC REPRESSOR DIMER BOUND TO OPERATOR AND THE ANTI-INDUCER ONPF

Summary for 1EFA

• Entry DOI: 10.2210/pdb1efa/pdb
• Descriptor: DNA (5'-D(*GP*AP*AP*T*TP*GP*TP*GP*AP*GP*CP*GP*CP*TP*CP*AP*CP*AP*AP*TP*T)-3'), LAC REPRESSOR, 2-nitrophenyl beta-D-fucopyranoside, ... (4 entities in total)
• Functional Keywords: protein-dna complex, helix-turn-helix, gene regulation, molecular switch, transcription-dna complex, transcription/dna
• Biological source: Escherichia coli
• Total number of polymer chains: 5
• Total formula weight: 121050.53

Authors

Bell, C.E.,Lewis, M. (deposition date: 2000-02-07, release date: 2000-03-06, Last modification date: 2024-02-07)

Primary citation

Bell, C.E.,Lewis, M.
A closer view of the conformation of the Lac repressor bound to operator.
Nat.Struct.Biol., 7:209-214, 2000

PubMed Abstract: Crystal structures of the Lac repressor, with and without isopropyithiogalactoside (IPTG), and the repressor bound to operator have provided a model for how the binding of the inducer reduces the affinity of the repressor for the operator. However, because of the low resolution of the operator-bound structure (4.8 A), the model for the allosteric transition was presented in terms of structural elements rather than in terms of side chain interactions. Here we have constructed a dimeric Lac repressor and determined its structure at 2.6 A resolution in complex with a symmetric operator and the anti-inducer orthonitrophenylfucoside (ONPF). The structure enables the induced (IPTG-bound) and repressed (operator-bound) conformations of the repressor to be compared in atomic detail. An extensive network of interactions between the DNA-binding and core domains of the repressor suggests a possible mechanism for the allosteric transition.

PubMed: 10700279
DOI: 10.1038/78907

Experimental method

X-RAY DIFFRACTION (2.6 Å)