The name of this superfamily has been modified since the most recent official CATH+ release (v4_3_0). At the point of the last release, this superfamily was named:

VpR/VpX protein, C-terminal domain

Functional Families

Overview of the Structural Clusters (SC) and Functional Families within this CATH Superfamily. Clusters with a representative structure are represented by a filled circle.

Superfamily: VpR/VpX protein, C-terminal domain

Human immunodeficiency virus (HIV) is the human retrovirus associated with AIDS (acquired immune deficiency syndrome), and SIV its simian counterpart. Three main groups of primate lentivirus are known, designated Human immunodeficiency virus 1 (HIV-1), Human immunodeficiency virus 2 (HIV-2)/Simian immunodeficiency virus - mac (SIVMAC)/Simian immunodeficiency virus - sm (SIVSM) and Simian immunodeficiency virus - agm (SIVAGM). Simian immunodeficiency virus - mnd (SIVMND) has been suggested to represent a fourth distinct group PMID:2797181. These groups are believed to have diverged from a common ancestor long before the spread of AIDS in humans. Genetic variation in HIV-1 and HIV-2 has been studied extensively, and the nucleotide sequences reported for several strains PMID:2611042.

HIVs contain several virion-associated (auxiliary) proteins, such as Vpr and Vpx.

Vpx plays a role in nuclear translocation of the viral pre-integration complex (PIC) and is thus required for the virus to infect non-dividing cells. Vpr also plays a role in nuclear translocation of the PIC and may target specific host proteins for degradation by the 26S proteasome. It acts by associating with the cellular CUL4A-DDB1 E3 ligase complex through direct interaction with host VPRPB/DCAF-1. This would result in cell cycle arrest or apoptosis in infected cells, creating a favourable environment for maximising viral expression and production by rendering the HIV-1 LTR transcription more active.

The C-terminal domain (52-96) of Vpr seems to be involved in the most important functions of the protein, such as DNA interaction and apoptosis via interaction with the adenine nucleotide translocator. Vpr contains a Leu/Ile-rich domain (amino acids 60-81) in its C-terminal part, which is critical for dimerisation PMID:15571493. The C-terminal domain (amino acids 52-96) of Vpr was shown to be involved in cell cycle arrest, to bind the nucleocapsid protein NCp7, and to interact with HIV-1 RNA. Furthermore, this domain is thought to promote nuclear provirus transfer.


GO Diversity

Unique GO annotations
15 Unique GO terms

EC Diversity

Unique EC annotations
0 Unique EC terms

Species Diversity

Unique species annotations
77 Unique species

Sequence/Structure Diversity

Overview of the sequence / structure diversity of this superfamily compared to other superfamilies in CATH. Click on the chart to view the data in more detail.

Superfamily Summary

A general summary of information for this superfamily.
Domains: 3
Domain clusters (>95% seq id): 1
Domain clusters (>35% seq id): 1
Unique PDBs: 2
Structural Clusters (5A): 1
Structural Clusters (9A): 1
FunFam Clusters: 1
Unique EC:
Unique GO: 15
Unique Species: 77