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Updated: Jul 19, 2026

Quantitation and Analysis of the Formation of HO-Endonuclease Stimulated Chromosomal Translocations by Single-Strand Annealing in Saccharomyces cerevisiae
09:40

Quantitation and Analysis of the Formation of HO-Endonuclease Stimulated Chromosomal Translocations by Single-Strand Annealing in Saccharomyces cerevisiae

Published on: September 23, 2011

Site-specific recombination intermediates trapped with suicide substrates

S E Nunes-Düby, L Matsumoto, A Landy

    Cell
    |August 28, 1987
    PubMed

    Insights

    Novel "suicide substrates" reveal that lambda site-specific recombination occurs via sequential single-strand exchanges, not concerted cutting. This order is protein-arrangement dependent and Integrase can perform nonreciprocal strand transfer.

    Area of Science:

    • Molecular Biology
    • Genetics
    • Biochemistry

    Background:

    • Site-specific recombination is a crucial DNA manipulation process.
    • Understanding the mechanism of lambda site-specific recombination is key to controlling genetic information.
    • Previous models proposed concerted DNA strand cutting, but lacked definitive evidence.

    Purpose of the Study:

    • To elucidate the precise mechanism of lambda site-specific recombination.
    • To investigate the role of protein arrangement in recombination order.
    • To determine the strand transfer capabilities of Integrase protein.

    Main Methods:

    • Design and utilization of novel "suicide substrates" with strategic nicks.
    • Analysis of accumulated reaction intermediates.
    • Characterization of Integrase protein's strand transfer activity.

    Main Results:

    • Lambda site-specific recombination proceeds through two sequential single-strand exchanges.
    • A concerted four-strand cutting model was definitively ruled out.
    • The order of strand exchange is invariant for both integration and excision.
    • Protein arrangement distal to exchange sites governs the strand exchange order.
    • Integrase protein demonstrated capacity for nonreciprocal single DNA strand transfer.

    Conclusions:

    • Lambda site-specific recombination mechanism involves sequential, ordered single-strand exchanges.
    • Protein-DNA interactions dictate the directionality of recombination.
    • Integrase possesses inherent capabilities for unidirectional strand transfer.

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