Structural highlights
Function
[TACY_STRP2] Sulfhydryl-activated toxin that causes cytolysis by forming pores in cholesterol containing host membranes. After binding to target membranes, the protein undergoes a major conformation change, leading to its insertion in the host membrane and formation of an oligomeric pore complex. Cholesterol may be required for binding to host membranes, membrane insertion and pore formation. Can be reversibly inactivated by oxidation (By similarity).
Publication Abstract from PubMed
Pneumolysin is a cholesterol-dependent cytolysin (CDC) and virulence factor of Streptococcus pneumoniae. It kills cells by forming pores assembled from oligomeric rings in cholesterol-containing membranes. Cryo-EM has revealed the structures of the membrane-surface bound pre-pore and inserted-pore oligomers, however the molecular contacts that mediate these oligomers are unknown because high-resolution information is not available. Here we have determined the crystal structure of full-length pneumolysin at 1.98 A resolution. In the structure, crystal contacts demonstrate the likely interactions that enable polymerisation on the cell membrane and the molecular packing of the pre-pore complex. The hemolytic activity is abrogated in mutants that disrupt these intermolecular contacts, highlighting their importance during pore formation. An additional crystal structure of the membrane-binding domain alone suggests that changes in the conformation of a tryptophan rich-loop at the base of the toxin promote monomer-monomer interactions upon membrane binding by creating new contacts. Notably, residues at the interface are conserved in other members of the CDC family, suggesting a common mechanism for pore and pre-pore assembly.
The Crystal Structure of Pneumolysin at 2.0 A Resolution Reveals the Molecular Packing of the Pre-pore Complex.,Marshall JE, Faraj BH, Gingras AR, Lonnen R, Sheikh MA, El-Mezgueldi M, Moody PC, Andrew PW, Wallis R Sci Rep. 2015 Sep 3;5:13293. doi: 10.1038/srep13293. PMID:26333773[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Marshall JE, Faraj BH, Gingras AR, Lonnen R, Sheikh MA, El-Mezgueldi M, Moody PC, Andrew PW, Wallis R. The Crystal Structure of Pneumolysin at 2.0 A Resolution Reveals the Molecular Packing of the Pre-pore Complex. Sci Rep. 2015 Sep 3;5:13293. doi: 10.1038/srep13293. PMID:26333773 doi:http://dx.doi.org/10.1038/srep13293
