Download MendeleyCrystal structure of the simian immunodeficiency virus (SIV) gp41 core: conserved helical interactions underlie the broad inhibitory activity of gp41 peptides.
Malashkevich, V.N., Chan, D.C., Chutkowski, C.T., Kim, P.S.(1998) Proc Natl Acad Sci U S A 95: 9134-9139
- PubMed: 9689046
- DOI: https://doi.org/10.1073/pnas.95.16.9134
- Primary Citation of Related Structures:
2SIV - PubMed Abstract:
The gp41 subunit of the envelope protein complex from human and simian immunodeficiency viruses (HIV and SIV) mediates membrane fusion during viral entry. The crystal structure of the HIV-1 gp41 ectodomain core in its proposed fusion-active state is a six-helix bundle. Here we have reconstituted the core of the SIV gp41 ectodomain with two synthetic peptides called SIV N36 and SIV C34, which form a highly helical trimer of heterodimers. The 2.2 A resolution crystal structure of this SIV N36/C34 complex is very similar to the analogous structure in HIV-1 gp41. In both structures, three N36 helices form a central trimeric coiled coil. Three C34 helices pack in an antiparallel orientation into highly conserved, hydrophobic grooves along the surface of this coiled coil. The conserved nature of the N36-C34 interface suggests that the HIV-1 and SIV peptides are functionally interchangeable. Indeed, a heterotypic complex between HIV-1 N36 and SIV C34 peptides is highly helical and stable. Moreover, as with HIV-1 C34, the SIV C34 peptide is a potent inhibitor of HIV-1 infection. These results identify conserved packing interactions between the N and C helices of gp41 and have implications for the development of C peptide analogs with broad inhibitory activity.
Organizational Affiliation:
Howard Hughes Medical Institute, Whitehead Institute for Biomedical Research, Department of Biology, Massachusetts Institute of Technology, Nine Cambridge Center, Cambridge, MA 02142, USA.
