2a5f
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| , resolution 2.02Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , and | ||||||
| Gene: | ARF6 (Homo sapiens), ctxA, toxA (Vibrio cholerae) | ||||||
| Activity: | NAD(+)--diphthamide ADP-ribosyltransferase, with EC number 2.4.2.36 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Cholera toxin A1 subunit bound to its substrate, NAD+, and its human protein activator, ARF6
OverviewOverview
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.
About this StructureAbout this Structure
2A5F is a Protein complex structure of sequences from Homo sapiens and Vibrio cholerae. Full crystallographic information is available from OCA.
ReferenceReference
Structural basis for the activation of cholera toxin by human ARF6-GTP., O'Neal CJ, Jobling MG, Holmes RK, Hol WG, Science. 2005 Aug 12;309(5737):1093-6. PMID:16099990
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