7PUD

Bryoporin - actinoporin from moss Physcomitrium patens

Summary for 7PUD

• Entry DOI: 10.2210/pdb7pud/pdb
• Descriptor: Bryoporin, (4S)-2-METHYL-2,4-PENTANEDIOL, SULFATE ION, ... (4 entities in total)
• Functional Keywords: actinoporin, membrane-binding, pore-formation, moss, plant protein
• Biological source: Physcomitrium patens (Spreading-leaved earth moss, Physcomitrella patens)
• Total number of polymer chains: 1
• Total formula weight: 22427.67

Authors

Solinc, G.,Anderluh, G.,Podobnik, M. (deposition date: 2021-09-29, release date: 2022-09-28, Last modification date: 2024-01-31)

Primary citation

Solinc, G.,Svigelj, T.,Omersa, N.,Snoj, T.,Pirc, K.,Znidarsic, N.,Yamaji-Hasegawa, A.,Kobayashi, T.,Anderluh, G.,Podobnik, M.
Pore-forming moss protein bryoporin is structurally and mechanistically related to actinoporins from evolutionarily distant cnidarians.
J.Biol.Chem., 298:102455-102455, 2022

PubMed Abstract: Pore-forming proteins perforate lipid membranes and consequently affect their integrity and cell fitness. 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, we provide the first detailed structural and functional analysis of this plant cytolysin. The crystal structure of monomeric bryoporin is highly similar to those of actinoporins. Our cryo-EM analysis of its pores showed an actinoporin-like octameric structure, thereby revealing a close kinship of proteins from evolutionarily distant organisms. This was further confirmed by our observation of bryoporin's preferential binding to and formation of pores in membranes containing animal sphingolipids, such as sphingomyelin and ceramide phosphoethanolamine; however, its binding affinity was weaker than that of actinoporin equinatoxin II. We determined bryoporin did not bind to major sphingolipids found in fungi or plants, and its membrane-binding and pore-forming activity was enhanced by various sterols. Our results suggest that bryoporin could represent a part of the moss defense arsenal, acting as a pore-forming toxin against membranes of potential animal pathogens, parasites, or predators.

PubMed: 36063994
DOI: 10.1016/j.jbc.2022.102455

Experimental method

X-RAY DIFFRACTION (1.25 Å)