The transcription fidelity factor GreA impedes DNA break repair

  • Nature volume 550, pages 214218 (12 October 2017)
  • doi:10.1038/nature23907
  • Download Citation


Homologous recombination repairs DNA double-strand breaks and must function even on actively transcribed DNA. Because break repair prevents chromosome loss, the completion of repair is expected to outweigh the transcription of broken templates. However, the interplay between DNA break repair and transcription processivity is unclear. Here we show that the transcription factor GreA inhibits break repair in Escherichia coli. GreA restarts backtracked RNA polymerase and hence promotes transcription fidelity. We report that removal of GreA results in markedly enhanced break repair via the classic RecBCD–RecA pathway. Using a deep-sequencing method to measure chromosomal exonucleolytic degradation, we demonstrate that the absence of GreA limits RecBCD-mediated resection. Our findings suggest that increased RNA polymerase backtracking promotes break repair by instigating RecA loading by RecBCD, without the influence of canonical Chi signals. The idea that backtracked RNA polymerase can stimulate recombination presents a DNA transaction conundrum: a transcription fidelity factor that compromises genomic integrity.

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We thank A. Gordon, G. Ira, D. Bates, H. Dierick, G. Shaulsky, and A. Barker for comments; I. Campbell for assistance with figure design; R. Nehring and M. Joshi for technical help; and S. Amundsen, W. Ross, A. Šimatovic´, C. Rudolph, M. Gottesman, J. Wang, and A. Poteete for sharing strains. The study was supported by National Institutes of Health (NIH) grant R01-GM088653 (C.H.), Dan L. Duncan Cancer Center and P30 CA125123 pilot grant (C.H., S.M.R.), a gift from the W. M. Keck Foundation (S.M.R.), NIH grants R35-GM122598 and DP1-CA174424 (S.M.R.), NIH grant RO1-GM082837 (I.G.), National Science Foundation PHY 1147498, PHY 1430124, PHY 1427654 (I.G.), the Welch Foundation (Q-1759), and the John S. Dunn Foundation (I.G.).

Author information


  1. Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA

    • Priya Sivaramakrishnan
    • , Jennifer A. Halliday
    • , Jingjing Liu
    • , María Angélica Bravo Núñez
    • , Susan M. Rosenberg
    •  & Christophe Herman
  2. Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA

    • Leonardo A. Sepúlveda
    • , Ido Golding
    •  & Susan M. Rosenberg
  3. Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA

    • Ido Golding
    • , Susan M. Rosenberg
    •  & Christophe Herman
  4. Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030, USA

    • Susan M. Rosenberg
    •  & Christophe Herman


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P.S. and C.H. conceived the study. P.S., J.A.H., and J.L. performed the experiments. M.A.B.N. and L.A.S. analysed the sequencing data. L.A.S. and I.G. performed the mathematical modelling of RecBCD. P.S., C.H., L.A.S., I.G., and S.M.R. wrote the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Christophe Herman.

Reviewer Information Nature thanks N. Savery and the other anonymous reviewer(s) for their contribution to the peer review of this work.

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    This file contains a list of bacterial strains used in the study.


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