What type of protease does HIV have?
The HIV protease is an aspartic protease and the catalytic site has the characteristic Asp-Thr-Gly sequence common to all aspartic proteases. It functions as a symmetric homodimer consisting of 99 amino acids per monomer.
How does HIV protease work?
HIV protease is responsible for processing of the gag and gag-pol polyproteins during virion maturation. The activity of this enzyme is essential for virus infectivity, rendering the protein a major therapeutic target for AIDS treatment. This articles reviews the biochemical and biophysical properties of the enzyme.
What is the pol gene?
Thepol gene encodes three enzymes, protease, RT, and IN. These proteins are synthesized from the same mRNA as the Gag proteins through a ribosomal translational frameshift. The cleavage of the 160-kDa precursor polyprotein is essential for viability.
What is the sequence of HIV?
The complexity of HIV sequences HIV-1 comprises three major groups –M, N, and O– which can be as much as 40% divergent. The M group is divided into subtypes A-K5, and inter-subtype recombination has been shown to be very common in geographic regions with a high prevalence of more than one subtype.
What does protease do in retroviruses?
Proteolytic processing of viral polyproteins is essential for retrovirus infectivity. Retroviral proteases (PR) become activated during or after assembly of the immature, non-infectious virion. They cleave viral polyproteins at specific sites, inducing major structural rearrangements termed maturation.
Which one of the following is a protease inhibitor?
There are ten HIV protease inhibitors approved by the FDA; those inhibitors include: saquinavir, indinavir, ritonavir, nelfinavir, amprenavir, fosamprenavir, lopinavir, atazanavir, tipranavir, and darunavir (Figure 2).
Why do retroviruses have two RNA strands?
Encapsidating two copies of genomic RNA is one of the characteristics of the retrovirus family. The two RNA molecules are both positive-sense and often identical; furthermore, each RNA encodes the full complement of genetic information required for viral replication.
What is a viral protease inhibitor?
6 days ago
Medications that inhibit the cleavage of the polyprotein into functional proteins are called protease inhibitors. Protease is a protein-based enzyme that normally breaks the polyprotein into functional proteins, so blocking, or inhibiting, protease prevents this essential step of viral reproduction.
How long have protease inhibitors been around?
The first protease inhibitor to be approved by the US Food and Drug Administration (FDA) was saquinavir, in December 1995, a mere 97 days after the FDA received its marketing application. Within months, two other protease inhibitors, ritonavir and indinavir, were also approved.
Are all RNA viruses retroviruses?
Retroviruses (Group VI) have a single-stranded RNA genome but, in general, are not considered RNA viruses because they use DNA intermediates to replicate.
Which of the following viruses has the ability to convert RNA to DNA?
RNA viruses, such as retroviruses, use the enzyme to reverse-transcribe their RNA genomes into DNA, which is then integrated into the host genome and replicated along with it.
When was the first protease inhibitor approved?
First Protease Inhibitor Becomes Available On December 6, 1995, just 6 months later—virtually a nanosecond on a typical drug approval timeline—saquinavir was approved for use in combination with other nucleoside analogue medications.
What is the HIV-1 genome sequence?
The complete sequence of the HIV-1 genome, extracted from infectious virions, has been solved to single- nucleotide resolution. The HIV genome encodes a small number of viral proteins, invariably establishing cooperative associations among HIV proteins and between HIV and host protein]s, to invade host cells and hijack their internal machineries.
What is HIV-1 protease?
Jump to navigation Jump to search. HIV-1 protease (PR) is a retroviral aspartyl protease (retropepsin), an enzyme involved with peptide bond hydrolysis in retroviruses, that is essential for the life-cycle of HIV, the retrovirus that causes AIDS.
What are HIV-1 protease and reverse transcriptase inhibitors?
The HIV-1 protease (PR) and reverse transcriptase (RT) enzymes are critical targets of these drug cocktails, and the U.S. Food and Drug Administration (FDA) has approved a number of PR inhibitors (PIs) as well as nucleoside/nucleotide and nonnucleoside RT inhibitors (NRTIs and NNRTIs, respectively).
Does HIV-1 protease variability affect Genotypic resistance testing?
HIV-1 protease (PR), reverse transcriptase (RT), and integrase (IN) variability presents a challenge to laboratories performing genotypic resistance testing.