2A5F

Cholera toxin A1 subunit bound to its substrate, NAD+, and its human protein activator, ARF6

Summary for 2A5F

• Entry DOI: 10.2210/pdb2a5f/pdb
• Descriptor: ADP-ribosylation factor 6, Cholera enterotoxin, A chain, MAGNESIUM ION, ... (8 entities in total)
• Functional Keywords: protein transport/transferase, protein transport-transferase complex
• Biological source: Homo sapiens (human); More
• Cellular location: Golgi apparatus: P62330
• Total number of polymer chains: 2
• Total formula weight: 43146.94

Authors

O'Neal, C.J.,Jobling, M.G.,Holmes, R.K.,Hol, W.G.J. (deposition date: 2005-06-30, release date: 2005-08-16, Last modification date: 2024-04-03)

Primary citation

O'Neal, C.J.,Jobling, M.G.,Holmes, R.K.,Hol, W.G.
Structural basis for the activation of cholera toxin by human ARF6-GTP.
Science, 309:1093-1096, 2005

PubMed Abstract: 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.

PubMed: 16099990
DOI: 10.1126/science.1113398

Experimental method

X-RAY DIFFRACTION (2.02 Å)