Pore-forming proteins perforate lipid membranes and consequently affect their integrity and cell fitness. Pore-forming proteins (PFPs) disrupt the normal functions of biological membranes by affecting their integrity and selective permeability. They are expressed by organisms of all kingdoms of life, with their biological roles spanning from involvement in immune response, development, digestion, and in most cases in attack or defense, thereby acting as toxins. PFPs are secreted by organisms as water-soluble monomers, which specifically or nonspecifically bind to either lipid, sugar, or protein components of the target membranes. The membrane-bound monomers then oligomerize into structured oligomers, followed by coordinated conformational changes in all protomers, resulting in formation of functional transmembrane pores. The transmembrane channels of these pores are either lined by symmetric α-helical clusters or β-barrels, based on which PFPs are classified into α- or β-PFPs. Therefore, it is not surprising that many of these proteins from bacteria, fungi, or certain animals act as toxins. While pore-forming proteins have also been found in plants, there is little information about their molecular structure and mode of action. Bryoporin is a protein from the moss Physcomitrium patens, and its corresponding gene was found to be upregulated by various abiotic stresses, especially dehydration, as well as upon fungal infection. Based on the amino acid sequence, it was suggested that bryoporin was related to the actinoporin family of pore-forming proteins, originally discovered in sea anemones. Here is the crystal structure of the bryoporin from moss Physcomitrium patens (PDB code: 7PUD)
#molecularart ... #immolecular ... #porin ... #toxin ... #poreforming ... #bryoporin ... #xray
Rendered with @proteinimaging and depicted with @corelphotopaint
#molecularart ... #immolecular ... #porin ... #toxin ... #poreforming ... #bryoporin ... #xray
Rendered with @proteinimaging and depicted with @corelphotopaint
