2ont
A swapped dimer of the HIV-1 capsid C-terminal domain
OverviewOverview
Assembly of the HIV and other retroviruses is primarily driven by the oligomerization of the Gag polyprotein, the major viral structural protein capable of forming virus-like particles even in the absence of all other virally encoded components. Several critical determinants of Gag oligomerization are located in the C-terminal domain of the capsid protein (CA-CTD), which encompasses the most conserved segment in the highly variable Gag protein called the major homology region (MHR). The CA-CTD is thought to function as a dimerization module, although the existing model of CA-CTD dimerization does not readily explain why the conserved residues of the MHR are essential for retroviral assembly. Here we describe an x-ray structure of a distinct domain-swapped variant of the HIV-1 CA-CTD dimer stabilized by a single amino acid deletion. In the domain-swapped structure, the MHR-containing segment forms a major part of the dimerization interface, providing a structural mechanism for the enigmatic function of the MHR in HIV assembly. Our observations suggest that swapping of the MHR segments of adjacent Gag molecules may be a critical intermediate in retroviral assembly.
About this StructureAbout this Structure
2ONT is a Single protein structure of sequence from Human immunodeficiency virus 1. Full crystallographic information is available from OCA.
ReferenceReference
Domain-swapped dimerization of the HIV-1 capsid C-terminal domain., Ivanov D, Tsodikov OV, Kasanov J, Ellenberger T, Wagner G, Collins T, Proc Natl Acad Sci U S A. 2007 Mar 13;104(11):4353-8. Epub 2007 Mar 5. PMID:17360528 Page seeded by OCA on Sun May 4 11:17:11 2008