Publication Date:
2005-08-16
Description:
The Vibrio cholerae bacterium causes devastating diarrhea when it infects the human intestine. The key event is adenosine diphosphate (ADP)-ribosylation of the human signaling protein GSalpha, catalyzed by the cholera toxin A1 subunit (CTA1). This reaction is allosterically activated by human ADP-ribosylation factors (ARFs), a family of essential and ubiquitous G proteins. Crystal structures of a CTA1:ARF6-GTP (guanosine triphosphate) complex reveal that binding of the human activator elicits dramatic changes in CTA1 loop regions that allow nicotinamide adenine dinucleotide (NAD+) to bind to the active site. The extensive toxin:ARF-GTP interface surface mimics ARF-GTP recognition of normal cellular protein partners, which suggests that the toxin has evolved to exploit promiscuous binding properties of ARFs.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉O'Neal, Claire J -- Jobling, Michael G -- Holmes, Randall K -- Hol, Wim G J -- AI-31940/AI/NIAID NIH HHS/ -- AI-34501/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 2005 Aug 12;309(5737):1093-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, University of Washington, Seattle, WA 98195, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16099990" target="_blank"〉PubMed〈/a〉
Keywords:
ADP-Ribosylation Factors/*chemistry/genetics/*metabolism
;
Amino Acid Sequence
;
Binding Sites
;
Cholera Toxin/*chemistry/genetics/*metabolism
;
Crystallography, X-Ray
;
Dimerization
;
Evolution, Molecular
;
Guanosine Diphosphate/metabolism
;
Guanosine Triphosphate/*chemistry/*metabolism
;
Humans
;
Hydrophobic and Hydrophilic Interactions
;
Models, Molecular
;
Molecular Sequence Data
;
NAD/metabolism
;
Protein Binding
;
Protein Conformation
;
Protein Structure, Secondary
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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