Publication Date:
1997-04-18
Description:
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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Soisson, S M -- MacDougall-Shackleton, B -- Schleif, R -- Wolberger, C -- GM18277/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1997 Apr 18;276(5311):421-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9103202" target="_blank"〉PubMed〈/a〉
Keywords:
AraC Transcription Factor
;
Arabinose/metabolism
;
*Bacterial Proteins
;
Binding Sites
;
Crystallization
;
Crystallography, X-Ray
;
DNA/*metabolism
;
Dimerization
;
Hydrogen Bonding
;
Ligands
;
Models, Molecular
;
*Protein Conformation
;
Protein Folding
;
Protein Structure, Secondary
;
Repressor Proteins/*chemistry/metabolism
;
*Transcription Factors
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink
