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Amplification, Next-generation Sequencing, and Genomic DNA Mapping of Retroviral Integration Sites
09:31

Amplification, Next-generation Sequencing, and Genomic DNA Mapping of Retroviral Integration Sites

Published on: March 22, 2016

Footprints on the viral DNA ends in moloney murine leukemia virus preintegration complexes reflect a specific

S Q Wei1, K Mizuuchi, R Craigie

  • 1Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.

Proceedings of the National Academy of Sciences of the United States of America
|September 2, 1998
PubMed

Insights

Moloney murine leukemia virus DNA integration involves preintegration complexes. Integrase protein binding to viral DNA ends, influenced by barrier-to-autointegration factor, is crucial for this process.

Area of Science:

  • Molecular Biology
  • Virology
  • Biochemistry

Background:

  • Retroviral DNA integration is a critical step in viral replication, mediated by the preintegration complex (PIC).
  • Understanding the nucleoprotein organization within PICs is essential for deciphering the integration mechanism.
  • Previous studies used Mu-mediated PCR to map protected regions on Moloney murine leukemia virus (MMLV) DNA ends within PICs.

Purpose of the Study:

  • To investigate the role of integrase and barrier-to-autointegration factor (BAF) in forming DNA-protein footprints within MMLV PICs.
  • To examine how mutations at the viral DNA termini affect PIC formation and DNA protection patterns.
  • To determine the relationship between viral DNA end structure and the initiation of integration.

Main Methods:

  • Mu-mediated PCR was employed to probe the nucleoprotein organization of MMLV PICs.
  • Analysis of footprints and enhancements at viral DNA termini in wild-type and mutant MMLV PICs.
  • Site-directed mutagenesis was used to alter viral DNA termini in replication-competent and incompetent mutants.

Main Results:

  • Specific association between integrase and viral DNA ends was confirmed in functional PICs.
  • Barrier-to-autointegration factor indirectly contributes to the formation of DNA-protein footprints.
  • A replication-competent mutant with a terminal deletion retained an enhancement at a fixed distance from the altered end.
  • A mutation rendering the virus replication-incompetent abolished enhancements and protection at both U3 and U5 ends.

Conclusions:

  • Integrase binding to viral DNA ends is a key feature of functional MMLV PICs.
  • The integrity of both viral DNA ends is necessary for proper complex formation and the initiation of 3' end processing.
  • These findings provide insights into the structural requirements for retroviral DNA integration.

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