Inverted repeats as genetic elements for promoting DNA inverted duplication: Implications in gene amplification

Ching Tai Lin, Wei Hsin Lin, Yi Lisa Lyu, Jacqueline Whang-Peng

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29 Citations (Scopus)

Abstract

Inverted repeats are important genetic elements for genome instability. In the current study we have investigated the role of inverted repeats in a DNA rearrangement reaction using a linear DNA substrate. We show that linear DNA substrates with terminal inverted repeats can efficiently transform Escherichia coli. The transformation products contain circular inverted dimers in which the DNA sequences between terminal inverted repeats are duplicated. In contrast to the recombination/rearrangement product of circular DNA substrates, which is exclusively one particular form of the inverted dimer, the rearrangement products of the linear DNA substrate consist of two isomeric forms of the inverted dimer. Escherichia coli mutants defective in RecBCD exhibit much reduced transformation efficiency, suggesting a role for RecBCD in the protection rather than destruction of these linear DNA substrates. These results suggest a model in which inverted repeats near the ends of a double-strand break can be processed by a helicase/exonuclease to form hairpin caps. Processing of hairpin capped DNA intermediates can then yield inverted duplications. Linear DNA substrates containing terminal inverted repeats can also be converted into inverted dimers in COS cells, suggesting conservation of this type of genome instability from bacteria to mammalian cells.

Original languageEnglish
Pages (from-to)3529-3538
Number of pages10
JournalNucleic Acids Research
Volume29
Issue number17
Publication statusPublished - Sep 1 2001
Externally publishedYes

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ASJC Scopus subject areas

  • Genetics

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