Figure 5-76. Transpositional site-specific recombination by a nonretroviral retrotransposon.

Figure 5-76Transpositional site-specific recombination by a nonretroviral retrotransposon

Transposition by the L1 element (red) begins when an endonuclease attached to the L1 reverse transcriptase and the L1 RNA (blue) makes a nick in the target DNA at the point at which insertion will occur. This cleavage releases a 3′-OH DNA end in the target DNA, which is then used as a primer for the reverse transcription step shown. This generates a single-stranded DNA copy of the element that is directly linked to the target DNA. In subsequent reactions, not yet understood in detail, further processing of the single-stranded DNA copy results in the generation of a new double-stranded DNA copy of the L1 element that is inserted at the site where the initial nick was made.

From: Site-Specific Recombination

Cover of Molecular Biology of the Cell
Molecular Biology of the Cell. 4th edition.
Alberts B, Johnson A, Lewis J, et al.
New York: Garland Science; 2002.
Copyright © 2002, Bruce Alberts, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, and Peter Walter; Copyright © 1983, 1989, 1994, Bruce Alberts, Dennis Bray, Julian Lewis, Martin Raff, Keith Roberts, and James D. Watson .

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