Prof David Leach
Dean of Academic Excellence

Contact details
- Tel: +44 (0)131 650 5373
- Email: D.Leach@ed.ac.uk
Address
- Street
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Rm. 1.12, Roger Land building
- City
- Post code
Background
1980 D.Phil., Sussex University
1980 - 1982 SERC Postdoctoral Fellow, Department of Molecular Biology, University of Oregon
1982 - 1983 MRC Postdoctoral Fellow, Department of Molecular Biology, University of Edinburgh
1983 - 1998 Lecturer, Department of Molecular Biology, University of Edinburgh
1998 -2002 Reader, Institute of Cell and Molecular Biology, University Edinburgh
2002 - Present Professor of Molecular Genetics, Institute of Cell and Molecular Biology, University of Edinburgh
2004 - 2008 Head of Institute, Institute of Cell Biology, University of Edinburgh
2008 - 2013 Head of School of Biological Sciences, University of Edinburgh
Undergraduate teaching
2nd year Genes and Gene Action
3rd year Molecular Genetics
4th year Biochemistry, Genetics and Molecular Biology
Research summary
Maintaining Genome Stability:
Applications and Implications of DNA Misfolding to Genetic Recombination, DNA Repair and Chromosome Segregation
The maintenance of genome stability relies on the interaction of DNA replication, repair and recombination, and it is becoming increasingly apparent that these are interconnected processes. Understanding of these processes promises to underpin our ability to respond appropriately to problems of wide importance such as genetic disease, cancer and ageing. Our interest in this field has led us to concentrate on a form of endogenous DNA damage - mis-folded DNA. DNA with internal symmetry (e.g. inverted repeats and simple sequence direct repeats) can mis-fold and cause genetic instability. This is a serious problem since DNA sequences with internal symmetry (e.g. tRNA sequences) are essential for life and simple repetitive sequences are common, can cause genetic diseases (e.g. Huntington's disease, myotonic dystrophy and fragile-X syndrome) and are rearranged in many cancers. We have developed assays for DNA mis-folding in living cells; initiated the study of the genetics and biochemistry of the E. coli SbcCD nuclease (Rad50/Mre11 in eukaryotes) which attacks mis-folded DNA; studied the pathway and consequences of double-strand break repair initiated by SbcCD-mediated cleavage; and are beginning to unravel the complex processing of trinucleotide repeats using E. coli model systems. Our aim is to generate an integrated understanding of replication, repair and recombination that goes beyond their initial discoveries as independent "pathways" and contributes to our understanding of how genome stability is maintained.
We are currently in the exciting position of using DNA misfolding as a tool to investigate the mechanisms of genetic recombination, DNA repair and chromosome segregation at defined chromosomal sites and welcome approaches from students interested in pursuing PhD studies and from postdoctoral scientists interested in contributing to this work.
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Distribution of Holliday junctions and repair forks during escherichia coli DNA double-strand break repair
(25 pages)
In:
PLoS Genetics, vol. 17
DOI: https://doi.org/10.1371/journal.pgen.1009717
Research output: Contribution to Journal › Article (Published) -
DNA targeting and interference by a bacterial Argonaute nuclease
(6 pages)
In:
Nature, vol. 587, pp. 632–637
DOI: https://doi.org/10.1038/s41586-020-2605-1
Research output: Contribution to Journal › Article (Published) -
The roles of bacterial DNA double-strand break repair proteins in chromosomal DNA replication
In:
FEMS microbiology reviews, pp. 1-18
DOI: https://doi.org/10.1093/femsre/fuaa009
Research output: Contribution to Journal › Article (Published) -
DNA double strand break repair in Escherichia coli perturbs cell division and chromosome dynamics
In:
PLoS Genetics, vol. 16
DOI: https://doi.org/10.1371/journal.pgen.1008473
Research output: Contribution to Journal › Article (Published) -
Genomic Analysis of DNA Double-Strand Break Repair in Escherichia coli
(32 pages)
DOI: https://doi.org/10.1016/bs.mie.2018.09.001
Research output: › Chapter (Published) -
Replication Fork Breakage and Restart in Escherichia coli
(19 pages)
In:
Microbiology and Molecular Biology Reviews, vol. 82
DOI: https://doi.org/10.1128/MMBR.00013-18
Research output: Contribution to Journal › Review article (Published) -
RecBCD coordinates repair of two ends at a DNA double-strand break, preventing aberrant chromosome amplification
(13 pages)
In:
Nucleic Acids Research, vol. 46, pp. 6670-6682
DOI: https://doi.org/10.1093/nar/gky463
Research output: Contribution to Journal › Article (Published) -
Dynamics of RecA-mediated repair of replication-dependent DNA breaks
In:
Journal of Cell Biology, vol. 217, pp. 2299-2307
DOI: https://doi.org/10.1083/jcb.201803020
Research output: Contribution to Journal › Article (Published) -
Broken replication forks trigger heritable DNA breaks in the terminus of a circular chromosome
(28 pages)
In:
PLoS Genetics, vol. 14
DOI: https://doi.org/10.1371/journal.pgen.1007256
Research output: Contribution to Journal › Article (Published) -
Division-induced DNA double strand breaks in the chromosome terminus region of Escherichia coli lacking RecBCD DNA repair enzyme
(30 pages)
In:
PLoS Genetics, vol. 13
DOI: https://doi.org/10.1371/journal.pgen.1006895
Research output: Contribution to Journal › Article (Published) -
RecG controls DNA amplification at double-strand breaks and arrested replication forks
In:
FEBS Letters
DOI: https://doi.org/10.1002/1873-3468.12583
Research output: Contribution to Journal › Article (Published) -
RecG directs DNA synthesis during double-strand break repair
(23 pages)
In:
PLoS Genetics, vol. 12
DOI: https://doi.org/10.1371/journal.pgen.1005799
Research output: Contribution to Journal › Article (Published) -
Long inverted repeat transiently stalls DNA replication by forming hairpin structures on both leading and lagging strands
(10 pages)
In:
Genes to Cells, vol. 21, pp. 136-145
DOI: https://doi.org/10.1111/gtc.12326
Research output: Contribution to Journal › Article (Published) -
Quantitative genomic analysis of RecA protein binding during DNA double-strand break repair reveals RecBCD action in vivo
In:
Proceedings of the National Academy of Sciences (PNAS), vol. 112
DOI: https://doi.org/10.1073/pnas.1424269112
Research output: Contribution to Journal › Article (Published) -
Chemical evolution of a bacterial proteome
(5 pages)
In:
Angewandte Chemie International Edition, vol. 54, pp. 10030-10034
DOI: https://doi.org/10.1002/anie.201502868
Research output: Contribution to Journal › Article (Published) -
A novel mode of nuclease action is revealed by the bacterial Mre11/Rad50 complex
(13 pages)
In:
Nucleic Acids Research, vol. 43, pp. 9804-9816
DOI: https://doi.org/10.1093/nar/gkv855
Research output: Contribution to Journal › Article (Published) -
Chromosomal directionality of DNA mismatch repair in Escherichia coli
(6 pages)
In:
Proceedings of the National Academy of Sciences (PNAS), vol. 112, pp. 9388-93
DOI: https://doi.org/10.1073/pnas.1505370112
Research output: Contribution to Journal › Article (Published) -
A perfect palindrome in the Escherichia coli chromosome forms DNA hairpins on both leading- and lagging-strands
(8 pages)
In:
Nucleic Acids Research, vol. 42, pp. 13206-13213
DOI: https://doi.org/10.1093/nar/gku1136
Research output: Contribution to Journal › Article (Published) -
Branch Migration Prevents DNA Loss during Double-Strand Break Repair
(13 pages)
In:
PLoS Genetics, vol. 10, pp. e1004485
DOI: https://doi.org/10.1371/journal.pgen.1004485
Research output: Contribution to Journal › Article (Published) -
Expansion of CAG repeats in Escherichia coli is controlled by single-strand DNA exonucleases of both polarities
(9 pages)
In:
Genetics, vol. 198, pp. 509-517
DOI: https://doi.org/10.1534/genetics.114.168245
Research output: Contribution to Journal › Article (Published)