6K2G

Structure of FraE in the monomer state

Summary for 6K2G

• Entry DOI: 10.2210/pdb6k2g/pdb
• Descriptor: FraE (2 entities in total)
• Functional Keywords: actinoporin, pore forming protein, toxin, protein evolution, hemolysis
• Biological source: Actinia fragacea
• Total number of polymer chains: 2
• Total formula weight: 39606.72

Authors

Caaveiro, J.M.M.,Morante, K.,Tsumoto, K. (deposition date: 2019-05-14, release date: 2020-03-25, Last modification date: 2023-11-22)

Primary citation

Morante, K.,Bellomio, A.,Viguera, A.R.,Gonzalez-Manas, J.M.,Tsumoto, K.,Caaveiro, J.M.M.
The Isolation of New Pore-Forming Toxins from the Sea AnemoneActinia fragaceaProvides Insights into the Mechanisms of Actinoporin Evolution.
Toxins, 11:-, 2019

PubMed Abstract: Random mutations and selective pressure drive protein adaptation to the changing demands of the environment. As a consequence, nature favors the evolution of protein diversity. A group of proteins subject to exceptional environmental stress and known for their widespread diversity are the pore-forming hemolytic proteins from sea anemones, known as actinoporins. In this study, we identified and isolated new isoforms of actinoporins from the sea anemone (fragaceatoxins). We characterized their hemolytic activity, examined their stability and structure, and performed a comparative analysis of their primary sequence. Sequence alignment reveals that most of the variability among actinoporins is associated with non-functional residues. The differences in the thermal behavior among fragaceatoxins suggest that these variability sites contribute to changes in protein stability. In addition, the protein-protein interaction region showed a very high degree of identity (92%) within fragaceatoxins, but only 25% among all actinoporins examined, suggesting some degree of specificity at the species level. Our findings support the mechanism of evolutionary adaptation in actinoporins and reflect common pathways conducive to protein variability.

PubMed: 31295915
DOI: 10.3390/toxins11070401

Experimental method

X-RAY DIFFRACTION (2.22 Å)