Reverse transcriptase from the simian immunodeficiency virus (SIV) was found to have kinetic behavior similar to that of enzyme from the human immunodeficiency virus (HIV). Michaelis constants for the substrates TTP and dGTP and inhibition constants for the inhibitors 3'-azido-3'-deoxythymidine 5'-triphosphate, 2',3'-dideoxythymidine 5'-triphosphate, and 2'-3'-dideoxyguanosine 5'-triphosphate w...

HIV-1 reverse transcriptase is a dimeric enzyme mainly involved in the replication of the viral genome. A filamentous phage cDNA expression library from human lymphocytes was used to select cellular proteins interacting with HIV-1 reverse transcriptase Affinity selections using the bacterially expressed monomeric large subunit of reverse transcriptase (p66) yielded host beta-actin. This clone w...

3’-Azido-3’-deoxythymidine 5’4riphosphate (AZTTP) was an efficient substrate for the human immunodeficiency virus 1 reverse transcriptase. It was incorporated into both homopolymer and defined sequence DNA-primed RNA templates and DNA-primed DNA templates. The substrate and inhibitor kinetics of both AZTTP and dTTP were dependent on the template-primer and reaction conditions used. dTMP was inc...

ES cells. This phenomenon has been observed in our laboratory in a number of cases. Clones putatively identified as homologous recombinants by Southern analysis can be quickly checked for random insertion of extra copies of the targeting vector by PCR. Given the small difference in size between the two alleles and use of only two primers common to both WT and mutant DNA, the amplification rate ...

Within each viral particle, retroviruses package two copies of a single-stranded RNA genome of about 10 kb. All of the viral genomes contain three major genes, arranged in the order: 5 ́-gag–pol–env-3 ́, and some retroviruses may also have accessory genes (e.g. vif, vpr, tax, etc...). Structural proteins such as MA (matrix protein), CA (capsid protein) and NC (nucleocapsid protein) are encoded wi...

In 1961, Howard Temin began to gather evidence that was inconsistant with the central dogma. Temin, who devoted his life to studying RNA tumor viruses (now known as retroviruses), focused his early work on Rous sarcoma virus (RSV). This RNA virus is capable of transforming normal cells into cancerous cells. Temin felt the best explanation for the virus’s behavior was a model whereby the virus r...

I n the past two decades, intense efforts have been devoted to uncovering the mechanisms responsible for the maintenance of telomeres in eukaryotic cells. These efforts have led to the identification of an unusual reverse transcriptase (RT), named telomerase, that uses an integral RNA subunit as template to synthesize a short reiterated sequence at the ends of eukaryotic chromosomes (Fig. 1A) (...

Currently, 16 antiretroviral drugs are approved for treatment of HIV infection. However, even the best currently available regimens pose challenges with regard to adherence, toxicity, antiviral activity, and resistance. New drug development thus confronts the need for improved convenience and tolerability, reduced toxicity, and improved activity against both wild-type and drug-resistant viruses...

Successful disease management requires a rapid and sensitive diagnosis method that can recognize early infection even before the manifestation of its clinical signs. The only available field diagnostic tests for foot-and-mouth disease (FMD) are lateral flow devices, commonly known as chromatographic strips. Low sensitivity and inability to detect FMD virus (FMDV) at the serotype level are limit...

Ribonuclease H (RNA.DNA-hybrid ribonucleotidohydrolase, EC 3.1.4.34) has been reported to copurify with reverse transcriptase (RNA directed DNA polymerase) of RNA tumor viruses. In addition, viral specific ribonuclease H and reverse transcriptase of avian type-C viruses are thought to be part of the same polypeptide. In this report we show that a fraction of the ribonuclease H activity from Rau...