Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A virus causing Jembrana disease in Bali cattle (Bos javanicus) was demonstrated to have characteristics of a retrovirus. Reverse transcriptase activity was detected in virus purified by sucrose gradient centrifugation. Electron microscopic examination of tissue from the affected cattle indicated that the virus matured by C-type budding through the plasma membrane and into intracytoplasmic vacuoles of cells in lymphoid tissue, with the formation of circular enveloped virus particles ranging in diameter from 96 to 124 nm with an eccentric nucleoid. Western immunoblotting using sera from recovered animals demonstrated virus proteins of M(r) 100K, 45K, 42K, 33K, 26K, 16K and 14K. The 26K protein of Jembrana disease virus cross-reacted in Western blots with the 26K capsid protein of bovine immunodeficiency virus (BIV). The apparent morphogenesis, protein structure and antigenic relationship with BIV suggested the virus was a lentivirus.
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PMID:Characteristics of a retrovirus associated with Jembrana disease in Bali cattle. 769 Aug 40

Human immunodeficiency viruses (HIVs) and the related bovine lentiviruses bovine immunodeficiency virus (BIV) and Jembrana disease virus (JDV) utilize the viral Tat protein to activate viral transcription. The arginine-rich RNA-binding domains of the Tat proteins bind to their cognate transactivation response element (TAR) RNA hairpins located at the 5' ends of the viral mRNAs, resulting in enhanced processivity of RNA polymerase II. It has previously been shown that HIV type 1 (HIV-1) Tat requires the cellular cyclin T1 protein for high-affinity RNA binding whereas BIV Tat and JDV Tat bind with high affinity on their own and adopt distinct beta-hairpin conformations when complexed to RNA. Here we have engineered the BIV and JDV Tat-TAR interactions into HIV-1 and show that the heterologous interactions support viral replication, correlating well with their RNA-binding affinities. Viruses engineered with a variant TAR able to bind all three Tat proteins replicate efficiently with any of the proteins. In one virus containing a noncognate Tat-TAR pair that neither interacts nor efficiently replicates (HIV-1 TAR and BIV Tat), viral revertants were isolated in which TAR had become mutated to generate a functional BIV Tat binding site. Our results support the view that incremental changes to TAR structure can provide routes for evolving new Tat-TAR complexes while maintaining active viral replication.
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PMID:Replication of human immunodeficiency viruses engineered with heterologous Tat-transactivation response element interactions. 1252 32

In the pol gene of bovine immunodeficiency virus (BIV) there is a sequence, located between the reverse-transcriptase and integrase (IN)-encoding sequences, that is not found in HIV-1 pol gene and encodes a 74-residue polypeptide with homology to dUTPases. We have expressed two BIV IN versions that differ in their amino termini. The longer version, containing the 74-residue sequence, did not show any detectable 3'-end processing and strand transfer IN activities and performed only the IN-associated disintegration. Consequently, the shorter version, lacking the dUTPase-related residues, performed all three activities and is most likely similar to the viral enzyme. A comparison between BIV IN and the well-studied HIV-1 IN, with substrates that mimic the U5 LTR sequences of BIV, HIV-1 and another bovine lentivirus, Jembrana disease virus, revealed that the extra 3'-end sequence beyond the conserved "CA" is probably less important for IN activities than the sequence upstream to the "CA".
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PMID:Expression and characterization of the integrase of bovine immunodeficiency virus. 1797 81