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2a5f
From Proteopedia
Contents |
Cholera toxin A1 subunit bound to its substrate, NAD+, and its human protein activator, ARF6
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.
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
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
2a5f is a 2 chain structure of Cholera toxin with sequence from Homo sapiens and Vibrio cholerae. Full crystallographic information is available from OCA.
See Also
Reference
- O'Neal CJ, Jobling MG, Holmes RK, Hol WG. Structural basis for the activation of cholera toxin by human ARF6-GTP. Science. 2005 Aug 12;309(5737):1093-6. PMID:16099990 doi:309/5737/1093
