Work

Extension and Cleavage of the Polypurine Tract Plus-strand Primer by Ty1 Reverse Transcriptase

Year: 2003

Type: article

Abstract: Using hybrid RNA/DNA substrates containing the polypurine tract (PPT) plus-strand primer, we have examined the interaction between the Ty1 reverse transcriptase (RT) and the plus-strand initiation complex. We show here that, although the PPT sequence is relatively resistant to RNase H cleavage, it can be cleaved internally by the polymerase-independent RNase H activity of Ty1 RT. Alternatively, this PPT can be used to initiate plus-strand DNA synthesis. We demonstrate that cleavage at the PPT/DNA junction occurs only after at least 9 nucleotides are extended. Cleavage leaves a nick between the RNA primer and the nascent plus-strand DNA. We show that Ty1 RT has a strand displacement activity beyond a gap but that the PPT is not efficiently re-utilized in vitro for another round of DNA synthesis after a first plus-strand DNA has been synthesized and cleaved at the PPT/U3 junction.

Source: Journal of Biological Chemistry

DOI: 10.1074/jbc.m305162200

Authors: François-Xavier Wilhelm, Marcelle Wilhelm, Abram Gabriel

Institutions: Institut de Biologie Moléculaire et Cellulaire, Rutgers, The State University of New Jersey

Language: English

Topic: Chromosomal and Genetic Variations

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funders: National Institutes of Health, National Institute of General Medical Sciences