4L63

Apo form of AB5 holotoxin

Summary for 4L63

• Entry DOI: 10.2210/pdb4l63/pdb
• Descriptor: ECXA, ECXB, ZINC ION, ... (5 entities in total)
• Functional Keywords: matrix metalloprotease, ab5 toxin, ob fold, cholera-like toxin, pentamer, toxin, protease, gm1, toxilysin, hydrolase
• Biological source: Escherichia coli; More
• Total number of polymer chains: 6
• Total formula weight: 94627.15

Authors

Littler, D.R.,Ng, N.M.,Rossjohn, J.,Beddoe, T. (deposition date: 2013-06-11, release date: 2013-11-27, Last modification date: 2024-11-06)

Primary citation

Ng, N.M.,Littler, D.R.,Paton, A.W.,Le Nours, J.,Rossjohn, J.,Paton, J.C.,Beddoe, T.
EcxAB Is a Founding Member of a New Family of Metalloprotease AB5 Toxins with a Hybrid Cholera-like B Subunit.
Structure, 21:2003-2013, 2013

PubMed Abstract: AB5 toxins are composed of an enzymatic A subunit that disrupts cellular function associated with a pentameric B subunit required for host cell invasion. EcxAB is an AB5 toxin isolated from clinical strains of Escherichia coli classified as part of the cholera family due to B subunit homology. Cholera-group toxins have catalytic ADP-ribosyltransferases as their A subunits, so it was surprising that EcxA did not. We confirmed that EcxAB self-associates as a functional toxin and obtained its structure. EcxAB is a prototypical member of a hybrid AB5 toxin family containing metzincin-type metalloproteases as their active A subunit paired to a cholera-like B subunit. Furthermore, EcxA is distinct from previously characterized proteases and thus founds an AB5-associated metzincin family that we term the toxilysins. EcxAB provides the first observation of conserved B subunit usage across different AB5 toxin families and provides evidence that the intersubunit interface of these toxins is far more permissive than previously supposed.

PubMed: 24095060
DOI: 10.1016/j.str.2013.08.024

Experimental method

X-RAY DIFFRACTION (1.8 Å)