Reverse transcriptase Reverse Transcriptase

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reverse transcriptase (RT-PCR) is a type of enzyme that exists in some RNA viruses and can synthesize DNA as a single-stranded RNA template. The DNA synthesized by reverse transcriptase-catalyzed reverse transcription is called complementary DNA (CDNA).

In general, intracellular transcription is the synthesis of RNA from DNA as a template, and the resulting RNA is used as a template for protein synthesis by messenger RNA (MRNA). In some RNA viruses, to achieve their own amplification, it is necessary to have DNA, so RNA is first synthesized by reverse transcription of cDNA and cDNA transcribed RNA.

Reverse transcriptase of HIV

Retrovirus, or Vissrna-rt virus, is an RNA retrovirus that uses DNA as an intermediate product. Their genomes are usually made up of two positive-sensing single-strand RNA with 5 ' end caps and 3 ' end-of-line poly-acid tails. Reverse transcriptase such as human immunodeficiency virus (HIV) and human T-lymphocyte virus HTLV. The process of producing double strands of DNA in the cytoplasm has the following steps ^[5]

1. The tRNA of a special cell is used as a primer and is hybridized with a complementary viral genome called the Primer Bonding bit or PBS.
2. The complementary DNA is then combined with the U5 (non-coding region) of the viral RNA and the R region (the repeating region at the end of the RNA).
3. The ribose nucleotides h on the reverse transcriptase will be used to remove RNA degradation at the 5 ' end of the U5 and R regions.
4. The primer then jumps to the 3 ' end of the viral genome and crosses the RNA with a newly created strand of DNA into complementary R-zones.
5. The first complementary DNA (CDNA) is extended and the main RNA of the virus is degraded by RNase H.
6. Once a share is complete, the second strand is synthesized from the beginning of the viral RNA.
7. The next one will jump to the second strand of PBS and Cross with the first complementary PBS.
8. The two strands will be stretched and incorporated into the host cells by the integrated enzymes.

Copy Fidelity

There are three different replication systems in the life history of Retrovirus. First, the reverse transcriptase synthesizes the viral DNA from the viral RNA, which in turn creates a new complementary DNA. The second replication is when the host cell's DNA polymerase begins to replicate the bonded viral DNA, and RNA polymerase II copies the DNA of the original virus into the RNA that is then packaged with the virus particles. Therefore, mutations can occur in these steps. ^[All]

The reverse transcriptase has a high error rate when it turns RNA into DNA, unlike other DNA polymerase, which does not have the correct function. This higher error rate can contribute to the accumulation of mutations relative to the corrected replication process. The reverse transcriptase, which is usually purchased by Promega in the market, says that there is a mutation in each of the 17,000 bases in the AMV, and one of every 30,000 bases in M-MLV is mutated. ^[]

In addition to the creation of a genetic diversity of mono-nucleotide, reverse transcriptase is also involved in some steps of primary product fusion or exon recombination and making artificial antisense RNA transcription products. [ ^{14] The switch of this template is speculated, this can be complete in vivo reaction of the reverse transcriptase, usually have to find in the pattern of organisms in the thousands of non-annotated transcription products.}

Antiviral drugs

For more details on antiviral drugs, refer to the reverse transcriptase inhibitor. When HIV uses reverse transcriptase to replicate the gene's substance and produce a new virus (part of the retrovirus's proliferative ring). Special drugs are designed to block the process of reverse transcriptase reactions and inhibit the growth of retrovirus. In general, these drugs are called reverse transcriptase inhibitors and contain a substance similar to nuclear gan and nucleotides, zidovudine (the product name is polygamy), lamivudine (Baraclude), and non-nucleoside inhibitors, Nevirapine (Vichy).

In eukaryotic organisms

The extended genome of self-replicating eukaryotic cells, called reverse transcription, is removed from one of the RNA locations by reverse transcriptase. They are found in a large number of genomes in plants and animals. Telomerase is another kind of reverse transcriptase, found in many eukaryotic organisms, such as those with their own RNA templates, that are used as templates for DNA replication. ^[9]

in the proto-nuclear organism

Reverse transcriptase is also from the bacterium Retron msr RNAs, a special fragment, encoded by the reverse transcriptase, and synthesized Msdna. A primer is needed to synthesize DNA. In bacteria, the synthesis of primers is made in the process of reproduction. ^[Ten]

Construction

The reverse transcriptase contains rna-dependent DNA polymerase and dna-dependent DNA polymerase, both of which are used to represent the transcription process. In the first transcription factor, the reverse transcriptase has an important area of the RNase H family.

Molecular Biology

For more details on molecular biology, refer to reverse transcription polymerase chain reaction (PCR). Reverse transcriptase is commonly used in polymerase chain reaction in this study, RNA-based technology is called reverse transcription polymerase chain reaction (RT-PCR). The typical PCR technique can only be used on DNA, but with the help of reverse transcriptase, RNA can also be turned into DNA, so that PCR is able to analyze RNA molecules. Reverse transcriptase is also used to make cDNA gene banks from mRNA, and the commercially available reverse transcriptase is often modified in the molecular biology world. Other enzymes allow scientists to perform the augmentation, or to define RNA.

Reverse transcriptase is also used in the production of insulin. By injecting the mRNA and reverse transcriptase of the eukaryotic cells into the bacteria, the mRNA can be inserted into the genome of the native organism. A large amount of insulin is made and can be used to replace the traditional way of extracting the islet from the pig. Direct DNA from eukaryotic cells is injected into the bacterial chromatin. In the production of eukaryotic mRNA, the intron is removed and an appropriate template is provided. The reverse transcriptase re-wove RNA into DNA so it can be bonded to the genome.

Reverse transcriptase Reverse Transcriptase