Structural highlights
Function
[ACTPC_ACTFR] Pore-forming protein that forms cations-selective hydrophilic pores of around 1 nm and causes cardiac stimulation and hemolysis. Pore formation is a multi-step process that involves specific recognition of membrane sphingomyelin (but neither cholesterol nor phosphatidylcholine) using aromatic rich region and adjacent phosphocholine (POC) binding site, firm binding to the membrane (mainly driven by hydrophobic interactions) accompanied by the transfer of the N-terminal region to the lipid-water interface and finally pore formation after oligomerization of several monomers.[1]
Publication Abstract from PubMed
The bidirectional transformation of a protein between its native water-soluble and integral transmembrane conformations is demonstrated for FraC, a hemolytic protein of the family of pore-forming toxins. In the presence of biological membranes, the water-soluble conformation of FraC undergoes a remarkable structural reorganization generating cytolytic transmembrane nanopores conducive to cell death. So far, the reverse transformation from the native transmembrane conformation to the native water-soluble conformation has not been reported. We describe the use of detergents with different physicochemical properties to achieve the spontaneous conversion of transmembrane pores of FraC back into the initial water-soluble state. Thermodynamic and kinetic stability data suggest that specific detergents cause an asymmetric change in the energy landscape of the protein, allowing the bidirectional transformation of a membrane protein.
Bidirectional Transformation of a Metamorphic Protein between the Water-Soluble and Transmembrane Native States.,Tanaka K, Caaveiro JM, Tsumoto K Biochemistry. 2015 Nov 24;54(46):6863-6. doi: 10.1021/acs.biochem.5b01112. Epub, 2015 Nov 11. PMID:26544760[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Bellomio A, Morante K, Barlic A, Gutierrez-Aguirre I, Viguera AR, Gonzalez-Manas JM. Purification, cloning and characterization of fragaceatoxin C, a novel actinoporin from the sea anemone Actinia fragacea. Toxicon. 2009 Nov;54(6):869-80. doi: 10.1016/j.toxicon.2009.06.022. Epub 2009 Jun, 27. PMID:19563820 doi:10.1016/j.toxicon.2009.06.022
- ↑ Tanaka K, Caaveiro JM, Tsumoto K. Bidirectional Transformation of a Metamorphic Protein between the Water-Soluble and Transmembrane Native States. Biochemistry. 2015 Nov 24;54(46):6863-6. doi: 10.1021/acs.biochem.5b01112. Epub, 2015 Nov 11. PMID:26544760 doi:http://dx.doi.org/10.1021/acs.biochem.5b01112
