2ARC

ESCHERICHIA COLI REGULATORY PROTEIN ARAC COMPLEXED WITH L-ARABINOSE

Summary for 2ARC

• Entry DOI: 10.2210/pdb2arc/pdb
• Related: 1XJA 2AAC 2ARA 2K9S
• Descriptor: ARABINOSE OPERON REGULATORY PROTEIN, alpha-L-arabinopyranose (3 entities in total)
• Functional Keywords: transcription factor, carbohydrate binding, coiled-coil, jelly roll
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 38441.39

Authors

Soisson, S.M.,Wolberger, C. (deposition date: 1996-10-29, release date: 1997-05-15, Last modification date: 2024-02-14)

Primary citation

Soisson, S.M.,MacDougall-Shackleton, B.,Schleif, R.,Wolberger, C.
Structural basis for ligand-regulated oligomerization of AraC.
Science, 276:421-425, 1997

PubMed Abstract: The crystal structure of the arabinose-binding and dimerization domain of the Escherchia coli gene regulatory protein AraC was determined in the presence and absence of L-arabinose. The 1.5 angstrom structure of the arabinose-bound molecule shows that the protein adopts an unusual fold, binding sugar within a beta barrel and completely burying the arabinose with the amino-terminal arm of the protein. Dimer contacts in the presence of arabinose are mediated by an antiparallel coiled-coil. In the 2.8 angstrom structure of the uncomplexed protein, the amino-terminal arm is disordered, uncovering the sugar-binding pocket and allowing it to serve as an oligomerization interface. The ligand-gated oligomerization as seen in AraC provides the basis of a plausible mechanism for modulating the protein's DNA-looping properties.

PubMed: 9103202
DOI: 10.1126/science.276.5311.421

Experimental method

X-RAY DIFFRACTION (1.5 Å)