The gag gene provides the basic physical infrastructure of the virus, and pol provides the basic mechanism by which retroviruses reproduce, while the others help HIV to enter the host cell and enhance its reproduction.

HIV (Human Immunodeficiency Virus) is composed of two strands of RNA, 15 types of viral proteins, and a few proteins from the last host cell it infected, all surrounded by a lipid bilayer membrane. Together, these molecules allow the virus to infect cells of the immune system and force them to build new copies of the virus.

HIV is able to enter the body via intact mucous membranes, eczematous or injured skin or mucosa and by parenteral inoculation. When transmitted by sexual contact, HIV attaches first to dendritic cells (e.g. Langerhans cells) or macrophages/monocytes; HIV using CCR-5 (R5 viruses) as a co-receptor is then preferentially replicated .

The overall structure of HIV is spherical, with an average diameter of approximately 120 nanometers. The virus has a complex life cycle involving multiple stages, including attachment and entry into host cells, reverse transcription, integration into the host genome, replication, and release of new virions.

Biology of HIV HIV (human immunodeficiency virus) is composed of two strands of RNA, 15 types of viral proteins, and a few proteins from the last host cell it infected, all surrounded by a lipid bilayer membrane.

HIV-1 and HIV-2 are the two known human retroviruses that belong to the genus Lentivirus (lentus, Latin for “slow”). 1.1.2. Structure of the virion. HIV-1 virions contain two copies of a single-stranded RNA genome within a conical capsid surrounded by a plasma membrane of host-cell origin containing viral envelope proteins.

This chapter describes our current understanding of HIV’s virion architecture and its dynamic transformations: the process of virion assembly as orchestrated by Gag, the architecture of the immature virion, the virus maturation process, and the structure of the mature capsid.

Dec 1, 2017 · HIV is a spherical virus of about 90 nm in diameter. HIV is enveloped virus. The envelope is a lipid bilayer surrounding the viral matrix, which is derived from host cell membrane during budding. Below the envelope, there is an icosahedral shell called matrix (P17). The core consists of cylindrical capsid (P24) which surrounds the genome.

The X-ray crystal structure of a core HIV-1 gp120 construct revealed the 3D fold of the critical viral glycoprotein as well as details of its interaction with the cell CD4 receptor and a neutralizing antibody.

Jan 8, 1999 · Infection of the host cell by HIV is initiated by interactions between SU and cell-surface CD4 molecules. SU binds to CD4 and anchors the virus to the cell surface, and additional interactions with chemokine receptors trigger a conformational change that leads to fusion of the viral and cellular membranes.