Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The recombinant reverse transcriptase of HIV-1 virus has been isolated from Escherichia coli cells transformed by the plasmid pRT40 DNA. The 103 Kd protein produced by these cells is shown to be processed to proteins with lower molecular masses by the reverse transcriptases own protease activity as well as Escherichia coli proteases. The resulting 103-66 Kd proteins possess the polymerase activity while 51 Kd and smaller proteins are lacking the activity. The 66 and 51 Kd reverse transcriptase fragments demonstrate the positive immunological reaction with the human blood serum from the people possessing antibodies to HIV-1 virus. The recombinant reverse transcriptase of HIV-1 produced by Escherichia coli cells is shown to be useful in AIDS diagnosis in humans.
Mol Gen Mikrobiol Virusol 1991 Mar
PMID:[Polymerase and immunologic activity of reverse transcriptase of the HIV-1 virus, isolated from Escherichia coli]. 171 97

The 16S ribosomal RNA sequences of Legionella pneumophila, L. erythra, L. hackeliae, L. spiritensis, L. longbeachae, L. bozemanii (Fluoribacter bozemanae) and L. micdadei (Tatlockia micdadei) were determined using reverse transcriptase. The sequences were compared with published sequences for Gram-negative bacteria and phylogenetic trees were constructed. The data confirm previous work which showed that the family Legionellaceae forms a monophyletic subgroup within the gamma subdivision of the Proteobacteria. The data show that all of the legionellae studied are highly related (greater than 95%) on the basis of 16S rRNA sequences and do not support the division of the family Legionellaceae into three genera.
J Gen Microbiol 1991 May
PMID:The use of 16S ribosomal RNA analyses to investigate the phylogeny of the family Legionellaceae. 171 50

Eighteen monoclonal antibodies (MAbs) directed against the purified human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) protein were produced. The antibodies were characterized by competitive ELISAs and Western blot experiments, and with nested, nine amino acid long peptides representing the whole 560 amino acid RT protein. By ELISA, the MAbs react with a minimum of seven epitopes of the protein. Four of the epitopes were located on the N-terminal 51K subunit and the remaining three epitopes were located at the C-terminal end of the protein. Using synthetic peptides, two epitopes at the N-terminal part were located at amino acids 294 to 302 and 350 to 354, respectively, from the N-terminal start of the protein. One epitope was located at amino acids 442 to 450, just after the cleavage site between the N-terminal and C-terminal subunit at position 440. Antibodies located at amino acids 294 to 302 could inhibit the RT enzymic activity of the protein. Two other MAbs, directed at the N-terminal and C-terminal parts of the protein, could also inhibit RT activity.
J Gen Virol 1991 Aug
PMID:Immunological characterization of the human immunodeficiency virus type 1 reverse transcriptase protein by the use of monoclonal antibodies. 171 42

To estimate the particle size of hepatitis C virus (HCV), a major causative agent of post-transfusion non-A, non-B hepatitis, we filtered plasma or serum samples through microporous cellulose fibres with different pore sizes. The amount of HCV particles in samples before and after filtration was determined by a quantitative reverse transcriptase polymerase chain reaction (PCR) method. Since there is no quantitative biological assay for HCV, except for that in chimpanzees, the HCV titre obtained from the PCR method was used in an equation constructed previously for application to filtration experiments with a flavivirus which is distantly related to HCV. The particle was estimated to be between 30 and 38 nm in diameter, although the possibility remained that larger HCV particles or HCV aggregates with a diameter of more than 39 nm might exist. Double-step filtration through microporous cellulose fibres with a pore size of 35 nm reduced the HCV content to below levels detectable by our PCR method, indicating that it is possible to eliminate HCV particles by simple filtration techniques.
J Gen Virol 1991 Aug
PMID:The particle size of hepatitis C virus estimated by filtration through microporous regenerated cellulose fibre. 171 47

Recently, we reported that hepatitis C virus (HCV) can be classified genetically into two types, HCV-K1 and HCV-K2, which show 67% and 71% identity at the nucleotide and amino acid sequence levels in a 340 bp region which encodes the NS5 gene Gly-Asp-Asp motif. To develop a rapid method to classify the genomes of HCV isolates, we identified restriction fragment length polymorphisms (RFLPs) in reverse transcriptase-polymerase chain reaction products encoding a portion of the NS5 gene. AluI and AccII enabled HCV to be classified into the K1 and K2 types, and Sau96I enabled classification into the K1 type, and the K2a and K2b subtypes. These RFLPs also generally allow Japanese isolates to be distinguished from the prototype (PT, an isolate from the U.S.A.), which is a K1 type. Sequence analysis of the 5'-untranslated regions of Japanese isolates revealed near identity between the K1 type and PT, and 93 to 94% identity between the K1 and K2 types, indicating that there are type K1- and K2-specific RFLPs in this region. Our results suggest that the nucleotide sequences of the K1 and K2 types are different throughout the HCV genome. The incidence of HCV types K1, K2a and K2b, and PT in 50 samples was 74%, 16%, 8% and 2%, respectively.
J Gen Virol 1991 Sep
PMID:Typing of hepatitis C virus genomes by restriction fragment length polymorphism. 171 52

Nasal exudate and tumour tissue from goats with enzootic nasal tumours were shown to contain a reverse transcriptase activity associated with a particle of buoyant density typical of retroviruses. The same particle contained a 25,000 Mr protein that cross-reacted with the p27 of Mason-Pfizer monkey virus (MPMV) and with p25 of sheep pulmonary adenomatosis retrovirus. It also contained a low Mr protein related to p10-12 of MPMV.
J Gen Virol 1991 Oct
PMID:Enzootic nasal tumour of goats: demonstration of a type D-related retrovirus in nasal fluids and tumours. 171 43

The spontaneous production and release of morphologically typical, 85 to 90 nm diameter C-type retrovirus particles from four cell lines derived from three species of warmwater fish have been identified. Virus pellets from cell culture supernatants showed high levels of Mn(2+)-dependent reverse transcriptase activity at 24 degrees C. Peak enzyme activity was associated with a 1 x 16 g/ml sucrose gradient fraction. All four isolates induced a cytolytic infection of a bluegill fry cell line within 6 to 10 days.
J Gen Virol 1991 Oct
PMID:Spontaneously productive C-type retrovirus infection of fish cell lines. 171 44

Bovine immunodeficiency virus (BIV) was purified by isodensity centrifugation; viral activities were monitored in gradient fractions using the reverse transcriptase assay and a p26-specific monoclonal antibody ELISA. In the coincident peak fractions (density about 1.17 g/ml) proteins with Mr values of 26K, 17K, 53K, 14K and 100K (with decreasing intensity) were detected by Western blotting using serum of a calf after experimental BIV infection. When 957 randomly collected cattle sera from The Netherlands were tested by indirect immunofluorescence and confirmed using Western blot and/or radioimmunoprecipitation, 1.4% appeared seropositive. Thus BIV infection is not uncommon in one European cattle population.
J Gen Virol 1991 Dec
PMID:Bovine immunodeficiency virus: immunochemical characterization and serological survey. 172 2

Under conditions in which a clonal cell line (M10) isolated from a human T cell lymphotrophic virus type I-transformed MT-4 cell line was completely killed by infection with wild-type human immunodeficiency virus type 1 (HIV-1), equivalent M10 cells survived infection with HIV-1 vif, vpr or vpu mutant virus after transient cytopathic effects. Several cell clones, which were isolated from the proliferating M10 cells after infection with vif and vpu mutant viruses (M10/vif- and M10/vpu-), had heterogeneous HIV-1 phenotypes in terms of HIV-1 antigen expression, their syncytium forming capacity, reverse transcriptase activity and the infectivity of HIV-1 particles produced. When the replication kinetics of the HIV-1 particles produced were assayed in M10 cells, the clones could be classified into three types, i.e. type I producing non-infectious HIV-1, type II producing infectious HIV-1 with low replicative ability and type III producing infectious HIV-1 with a replicative ability similar to that of wild-type HIV-1. HIV-1 major viral cell proteins and virus particle fractions were almost typical in types II and III but not in type I. Electron microscopic examination of particles released by I, II and III clones revealed rare defective, predominantly defective and essentially normal virions, respectively. Northern and Southern blot analyses revealed no apparent deletion in the proviral DNA and mRNA prepared from these clones, except in the case of type I and II clones isolated from M10/vpu- which contained large deletions in the mRNAs for gag and gag-pol proteins. Thus, M10 cells surviving infection with HIV-1 vif or vpu mutants are heterogeneous, persistently expressing HIV-1 antigens and producing non-infectious or less cytopathic virus.
J Gen Virol 1992 Jan
PMID:Cells surviving infection by human immunodeficiency virus type 1: vif or vpu mutants produce non-infectious or markedly less cytopathic viruses. 173 Sep 43

The preparations of purified Marburg virus were isolated from blood plasma of infected guinea pigs and characterized. Viral RNA was extracted from the virions. The cDNA was synthesized on the isolated RNA matrix by the reverse transcriptase with the use of dissipated priming. The obtained cDNA was inserted into the plasmid pBR322 by the connector technique and the resulting recombinant plasmids were cloned in Escherichia coli cells. The specific clones selected by molecular hybridization method were analyzed by the restriction mapping and cross-hybridization. Four overlapping cDNA clones were found and the virus specific 5012 bp fragment of the viral genome was sequenced. Three open reading frames were found and the preliminary analysis of the coded amino acid sequence and corresponding genes was fulfilled.
Mol Gen Mikrobiol Virusol 1991 Mar
PMID:[Marburg virus: the first determined nucleotide sequence of two genes]. 185 71


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