6UZE

Anthrax toxin protective antigen channels bound to edema factor

Summary for 6UZE

• Entry DOI: 10.2210/pdb6uze/pdb
• Related: 6UZB 6UZD
• EMDB information: 20955 20957 20958
• Descriptor: Protective antigen, Calmodulin-sensitive adenylate cyclase, CALCIUM ION (3 entities in total)
• Functional Keywords: translocase, anthrax toxin, protective antigen, edema factor
• Biological source: Bacillus anthracis; More
• Total number of polymer chains: 9
• Total formula weight: 757854.04

Authors

Hardenbrook, N.J.,Liu, S.,Zhou, K.,Zhou, Z.H.,Krantz, B.A. (deposition date: 2019-11-15, release date: 2020-03-04, Last modification date: 2024-03-06)

Primary citation

Hardenbrook, N.J.,Liu, S.,Zhou, K.,Ghosal, K.,Hong Zhou, Z.,Krantz, B.A.
Atomic structures of anthrax toxin protective antigen channels bound to partially unfolded lethal and edema factors.
Nat Commun, 11:840-840, 2020

PubMed Abstract: Following assembly, the anthrax protective antigen (PA) forms an oligomeric translocon that unfolds and translocates either its lethal factor (LF) or edema factor (EF) into the host cell. Here, we report the cryo-EM structures of heptameric PA channels with partially unfolded LF and EF at 4.6 and 3.1-Å resolution, respectively. The first α helix and β strand of LF and EF unfold and dock into a deep amphipathic cleft, called the α clamp, which resides at the interface of two PA monomers. The α-clamp-helix interactions exhibit structural plasticity when comparing the structures of lethal and edema toxins. EF undergoes a largescale conformational rearrangement when forming the complex with the channel. A critical loop in the PA binding interface is displaced for about 4 Å, leading to the weakening of the binding interface prior to translocation. These structures provide key insights into the molecular mechanisms of translocation-coupled protein unfolding and translocation.

PubMed: 32047164
DOI: 10.1038/s41467-020-14658-6

Experimental method

ELECTRON MICROSCOPY (3.4 Å)