A sequestered fusion peptide in the structure of an HIV-1 transmitted founder envelope trimer.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30787293.
- Also identified by DOI 10.1038/s41467-019-08825-7 and PMC identifier 6382815.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The envelope protein of human immunodeficiency virus-1 (HIV-1) and its fusion peptide are essential for cell entry and vaccine design. Here, we describe the 3.9-Å resolution structure of an envelope protein trimer from a very early transmitted founder virus (CRF01_AE T/F100) complexed with Fab from the broadly neutralizing antibody (bNAb) 8ANC195. The overall T/F100 trimer structure is similar to other reported "closed" state prefusion trimer structures. In contrast, the fusion peptide, which is exposed to solvent in reported closed structures, is sequestered (buried) in the hydrophobic core of the T/F100 trimer. A buried conformation has previously been observed in "open" state structures formed after CD4 receptor binding. The T/F100 trimer binds poorly to bNAbs including the fusion peptide-specific bNAbs PGT151 and VRC34.01. The T/F100 structure might represent a prefusion state, intermediate between the closed and open states. These observations are relevant to mechanisms of HIV-1 transmission and vaccine design.
Medical subject headings
- Antibodies, Neutralizing
- HIV Antibodies
- HIV-1
- Immunoglobulin Fab Fragments
- env Gene Products, Human Immunodeficiency Virus