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  • M Baez, R Taussig, +4 authors A M Skalka
  • 1980
The nucleotide sequence of the NS gene of the human influenza virus A/PR/8/34 was determined and found to be the same length (890 nucleotides) as the NS gene of another human influenza virus A/Udorn/72 and of the avian isolate A/FPV/Rostock/34. Comparison of the sequences of the NS genes of the two human influenza viruses shows an 8.9% difference whereas(More)
Vertebrate genomes contain numerous copies of retroviral sequences, acquired over the course of evolution. Until recently they were thought to be the only type of RNA viruses to be so represented, because integration of a DNA copy of their genome is required for their replication. In this study, an extensive sequence comparison was conducted in which 5,666(More)
Integration of retroviral DNA into the host chromosome requires a virus-encoded integrase (IN). IN recognizes, cuts and then joins specific viral DNA sequences (LTR ends) to essentially random sites in host DNA. We have used computer-assisted protein alignments and mutagenesis in an attempt to localize these functions within the avian retroviral IN protein.(More)
The integration of viral DNA into the host cell chromosome is an essential feature of the retroviral life cycle. The integration reaction requires cis-acting sequences at the ends of linear viral DNA and a trans-acting product of the pol gene, the integration protein (IN). Previously, we demonstrated that avian sarcoma-leukosis virus (ASLV) IN is able to(More)
Retroviral integrase, one of only three enzymes encoded by the virus, catalyzes the essential step of inserting a DNA copy of the viral genome into the host during infection. Using the avian sarcoma virus integrase, we demonstrate that the enzyme functions as a tetramer. In presteady-state active site titrations, four integrase protomers were required for a(More)
The human immunodeficiency virus (HIV-1) encodes a protease that is essential for viral replication and is a member of the aspartic protease family. The recently determined three-dimensional structure of the related protease from Rous sarcoma virus has been used to model the smaller HIV-1 dimer. The active site has been analyzed by comparison to the(More)
The composition and subcellular trafficking of subviral preintegration complexes are reported to vary among the different retroviruses. The process by which the avian sarcoma virus (ASV) preintegration complex gains access to target chromatin remains unknown. Here we report that ASV integrase (IN) expressed as a fusion to beta-galactosidase accumulates in(More)
It has been generally believed that oncoretroviruses are dependent on mitosis for efficient nuclear entry of viral DNA. We previously identified a nuclear localization signal in the integrase protein of an oncoretrovirus, avian sarcoma virus (ASV), suggesting an active import mechanism for the integrase-DNA complex (G. Kukolj, R. A. Katz, and A. M. Skalka,(More)
Six crystal structures of the core domain of integrase (IN) from avian sarcoma virus (ASV) and its active-site derivative containing an Asp64 --> Asn substitution have been solved at atomic resolution ranging 1.02-1.42 A. The high-quality data provide new structural information about the active site of the enzyme and clarify previous inconsistencies in the(More)