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. 1989 Apr;86(8):2525–2529. doi: 10.1073/pnas.86.8.2525

Retroviral integration: structure of the initial covalent product and its precursor, and a role for the viral IN protein.

P O Brown 1, B Bowerman 1, H E Varmus 1, J M Bishop 1
PMCID: PMC286949  PMID: 2539592

Abstract

An essential step in the life cycle of a retrovirus is the integration of a DNA copy of the viral genome into a host cell chromosome. We have analyzed the structure of the initial covalent product of an in vitro retroviral integration reaction and determined the structure of the ends of the unintegrated linear viral DNA molecules present in vivo in cells infected with murine leukemia virus (MLV). Our results lead to the following conclusions: (i) Circularization of viral DNA plays no role in integration. The direct precursor to the integrated MLV provirus is a linear molecule. (ii) The initial step in the integration reaction is probably a cleavage that removes the terminal 2 bases from each 3' end of the viral DNA. This cleavage depends on a virally encoded protein, IN, that has previously been shown genetically to be required for integration. (iii) The resulting viral 3' ends are joined to target DNA to form the initial recombination intermediate.

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These references are in PubMed. This may not be the complete list of references from this article.

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