8VXV

HIV-1 R18L CA hexamer

Summary for 8VXV

• Entry DOI: 10.2210/pdb8vxv/pdb
• Related: 8vxw
• EMDB information: 43641
• Descriptor: Capsid protein p24 (1 entity in total)
• Functional Keywords: capsid, virus like particle
• Biological source: Human immunodeficiency virus 1
• Total number of polymer chains: 1
• Total formula weight: 25586.39

Authors

Schirra, R.T.,Pornillos, O.,Ganser-Pornillos, B.K. (deposition date: 2024-02-06, release date: 2025-12-31)

Primary citation

Schirra, R.T.,Dos Santos, N.F.B.,Ganser-Pornillos, B.K.,Pornillos, O.
Arg18 Substitutions Reveal the Capacity of the HIV-1 Capsid Protein for Non-Fullerene Assembly.
Viruses, 16:-, 2024

PubMed Abstract: In the fullerene cone HIV-1 capsid, the central channels of the hexameric and pentameric capsomers each contain a ring of arginine (Arg18) residues that perform essential roles in capsid assembly and function. In both the hexamer and pentamer, the Arg18 rings coordinate inositol hexakisphosphate, an assembly and stability factor for the capsid. Previously, it was shown that amino-acid substitutions of Arg18 can promote pentamer incorporation into capsid-like particles (CLPs) that spontaneously assemble in vitro under high-salt conditions. Here, we show that these Arg18 mutant CLPs contain a non-canonical pentamer conformation and distinct lattice characteristics that do not follow the fullerene geometry of retroviral capsids. The Arg18 mutant pentamers resemble the hexamer in intra-oligomeric contacts and form a unique tetramer-of-pentamers that allows for incorporation of an octahedral vertex with a cross-shaped opening in the hexagonal capsid lattice. Our findings highlight an unexpected degree of structural plasticity in HIV-1 capsid assembly.

PubMed: 39066201
DOI: 10.3390/v16071038

Experimental method

ELECTRON MICROSCOPY (3.7 Å)