A triclinic crystal structure of the carboxy-terminal domain of HIV-1 capsid protein with four molecules in the asymmetric unit reveals a novel packing interface.Lampel, A., Yaniv, O., Berger, O., Bacharach, E., Gazit, E., Frolow, F.
(2013) Acta Crystallogr.,Sect.F 69: 602-606
- PubMed: 23722834
- DOI: 10.1107/S1744309113011871
- PubMed Abstract:
The Gag precursor is the major structural protein of the virion of human immunodeficiency virus-1 (HIV-1). Capsid protein (CA), a cleavage product of Gag, plays an essential role in virus assembly both in Gag-precursor multimerization and in capsid c ...
The Gag precursor is the major structural protein of the virion of human immunodeficiency virus-1 (HIV-1). Capsid protein (CA), a cleavage product of Gag, plays an essential role in virus assembly both in Gag-precursor multimerization and in capsid core formation. The carboxy-terminal domain (CTD) of CA contains 20 residues that are highly conserved across retroviruses and constitute the major homology region (MHR). Genetic evidence implies a role for the MHR in interactions between Gag precursors during the assembly of the virus, but the structural basis for this role remains elusive. This paper describes a novel triclinic structure of the HIV-1 CA CTD at 1.6 Å resolution with two canonical dimers of CA CTD in the asymmetric unit. The canonical dimers form a newly identified packing interface where interactions of four conserved MHR residues take place. This is the first structural indication that these MHR residues participate in the putative CTD-CTD interactions. These findings suggest that the molecules forming this novel interface resemble an intermediate structure that participates in the early steps of HIV-1 assembly. This interface may therefore provide a novel target for antiviral drugs.
Molecular Microbiology and Biotechnology, Tel Aviv University, 69978 Tel Aviv, Israel.