Atomic structure of a thermostable subdomain of HIV-1 gp41.
Infection by HIV-1 involves the fusion of viral and cellular membranes with subsequent transfer of viral genetic material into the cell. The HIV-1 envelope glycoprotein that mediates fusion consists of the surface subunit gp120 and the transmembrane subunit gp41. gp120 directs virion attachment to the cell-surface receptors, and gp41 then promotes viral-cell membrane fusion. A soluble, alpha-helical, trimeric complex within gp41 composed of N-terminal and C-terminal extraviral segments has been proposed to represent the core of the fusion-active conformation of the HIV-1 envelope. A thermostable subdomain denoted N34(L6)C28 can be formed by the N-34 and C-28 peptides connected by a flexible linker in place of the disulfide-bonded loop region. Three-dimensional structure of N34(L6)C28 reveals that three molecules fold into a six-stranded helical bundle. Three N-terminal helices within the bundle form a central, parallel, trimeric coiled coil, whereas three C-terminal helices pack in the reverse direction into three hydrophobic grooves on the surface of the N-terminal trimer. This thermostable subdomain displays the salient features of the core structure of the isolated gp41 subunit and thus provides a possible target for therapeutics designed selectively to block HIV-1 entry.
Tan
K
K
Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
Liu
J
J
Wang
J
J
Shen
S
S
Lu
M
M
D000595:Amino Acid Sequence; D015700:HIV Envelope Protein gp41 / Q000737:chemistry*; D015497:HIV-1 / Q000737:chemistry*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D013696:Temperature
D015700:HIV Envelope Protein gp41