Protective antigen, heptamerisation domain (IPR027439)

Short name: PA_heptamer_dom

Overlapping homologous superfamilies

Domain relationships



Protective antigen (PA) is the central component of the three-part protein toxin secreted by Bacillus anthracis, the organism responsible for anthrax. Homologues of PA have been found in several spore-forming Gram-positive bacteria, and share the ability to translocate toxic enzymes into the host cytosol.The PA monomer is organised mainly into antiparallel beta-sheets and has four domains: an N-terminal domain (domain 1) containing two calcium ions and the cleavage site for activating proteases; a heptamerisation domain (domain 2) containing a large flexible loop implicated in membrane insertion; a small domain of unknown function (domain 3); and a carboxy-terminal receptor-binding domain (domain 4) [PMID: 9039918].

This entry represents domain 2 of PA.

GO terms

Biological Process

GO:0051260 protein homooligomerization

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.