Charge-surrounded pockets and electrostatic interactions with small ions modulate the activity of retroviral fusion proteins.

• الحاوية / القاعدة: PLoS Pathogens
• المؤلفون الرئيسيون: Daniel Lamb, Alexander W Schüttelkopf, Daan M F van Aalten, David W Brighty
• التنسيق: مقال
• اللغة: الإنجليزية
• منشور في: Public Library of Science (PLoS) 2011-02-01
• الوصول للمادة أونلاين: https://journals.plos.org/plospathogens/article/file?id=10.1371/journal.ppat.1001268&type=printable
• تدمد: 1553-7366; 1553-7374

Refolding of viral class-1 membrane fusion proteins from a native state to a trimer-of-hairpins structure promotes entry of viruses into cells. Here we present the structure of the bovine leukaemia virus transmembrane glycoprotein (TM) and identify a group of asparagine residues at the membrane-distal end of the trimer-of-hairpins that is strikingly conserved among divergent viruses. These asparagines are not essential for surface display of pre-fusogenic envelope. Instead, substitution of these residues dramatically disrupts membrane fusion. Our data indicate that, through electrostatic interactions with a chloride ion, the asparagine residues promote assembly and profoundly stabilize the fusion-active structures that are required for viral envelope-mediated membrane fusion. Moreover, the BLV TM structure also reveals a charge-surrounded hydrophobic pocket on the central coiled coil and interactions with basic residues that cluster around this pocket are critical to membrane fusion and form a target for peptide inhibitors of envelope function. Charge-surrounded pockets and electrostatic interactions with small ions are common among class-1 fusion proteins, suggesting that small molecules that specifically target such motifs should prevent assembly of the trimer-of-hairpins and be of value as therapeutic inhibitors of viral entry.