Institut de Biologie StructuraleGrenoble / France

Contact person(s) related to this article / TIMMINS Joanna


DNA Damage and Repair

Team leader : Joanna Timmins

The prime objective for every life form is to deliver its genetic material, intact and unchanged, to the next generation, despite constant assaults from both endogenous and environmental sources on the DNA. DNA lesions can block genome replication and transcription, and if left unrepaired can lead to mutations or wider-scale genome aberrations that threaten cell or organism viability. To counter this threat, cells have evolved several elaborate DNA damage response systems.

Research projects
1. Our team studies the molecular mechanisms underlying DNA damage recognition and repair in the radiation-resistant bacterium Deinococcus radiodurans. Our work focuses on two major aspects, which are :

- Dynamics of DNA Damage Repair Processes
- Recognition of DNA Lesions

Our goal is to use a combination of Structural Biology methods and Biophysical and Biochemical tools to decipher the complex molecular processes leading to efficient repair of DNA lesions.

2. Our team also studies the organisation and dynamics of Deinococcus radiodurans nucleoids that present several unusual features : they adopt a toroidal shape and are highly condensed.

Here our goal is to use structural biology and biochemical approaches together with live cell imaging techniques (conventional and super resolution PALM/PAINT fluorescence microscopy) to better understand the mechanisms underlying nucleoid organisation and chromosome segregation during cell division.

3. Finally, our team also studies DNA repair enzymes from humans and in particular we are studying the interaction between a DNA glycosylase, hNTH1, and a transcription factor, YB1. This complex is involved in anti-cancer drug resistance in solid tumours treated with cisplatin.

Key Words :
DNA repair, Lesion recognition, Dynamics, Nucleoid, Cancer

Techniques :
- Expression and purification of proteins
- Biochemical/biophysical characterization
- DNA binding and activity assays
- Protein crystallography
- Small-angle scattering
- Fluorescence-based assays, FRET
- Conventional and super-resolution microscopy

Team members :
- Fabienne Hans, MCF UGA
- Françoise Lacroix, IE CNRS
- Salvatore De Bonis, CEA Technician
- Pierre Vauclare, CR CNRS
- Anne-Sophie Banneville, PhD student
- Kevin Floc’h, PhD student
- Anna Seck, PhD student
- Anthoula Mettou, post-doc

Publications :

Floc’h K, Lacroix F, Barbieri L, Servant P, Galland R, Butler C, Sibarita JB, Bourgeois D and Timmins J. Bacterial cell wall nanoimaging by autoblinking microscopy. Scientific Reports (2018) 8 (1) p. 14038.

Wiegand T, Cadalbert R, Gardiennet C, Timmins J, Terradot L, Böckmann A, Meier BH. Monitoring ssDNA Binding to the DnaB Helicase from Helicobacter pylori by Solid-State NMR Spectroscopy. Angew Chem Int Ed Engl. (2016) 55 (45) p.14164-14168.

Timmins J and Moe E. A decade of biochemical and structural studies of the DNA repair machinery of Deinococcus radiodurans. Review article. Comput Struct Biotechnol J. (2016) 14 p. 168-176.

Bazin A, Cherrier M, Gutsche I, Timmins J and Terradot L. Structure and primase-mediated activation of a bacterial dodecameric replicative helicase. Nucleic Acids Research (2015) 43 (17) p. 8564-76.

Sarre A, Ökvist M, Klar T, Hall DR, Smålas A, McSweeney S, Moe E and Timmins J. Structural and functional characterization of two unusual endonuclease III enzymes from Deinococcus radiodurans. Journal of Structural Biology (2015) 191 (2) p. 87-99.

Sarre A, Ökvist M, Klar T, Moe E and Timmins J. Expression, purification and crystallization of two endonuclease III enzymes from Deinococcus radiodurans. Acta Crys. (2014) F70 p.1688-1692.

Stelter M, Acajjaoui S, McSweeney S and Timmins J (2013). Structural and functional characterization of drUvrD provide new insights into DNA unwinding and helicase polarity. PLoS ONE 8 (10) : e77364.

Radzimanowski J, Dehez F, Round A, Bidon-Chanal A, McSweeney S and Timmins J (2013). An ‘open’ structure of the RecOR complex supports ssDNA binding within the core of the complex. Nucleic Acids Research 41 (16) p.7972-7986.

Pellegrino S, Radzimanowski J, de Sanctis D, Boeri Erba E, McSweeney S and Timmins J (2012). Crystal structures of D. radiodurans RecN : New insight into double-strand break repair. Structure 20 p.2076-2089.

Moe E, Hall DR, Leiros I, Talstad V, Timmins J, McSweeney S. Structure/function studies of an unusual 3-methyladenine DNA glycosylase II (AlkA) from Deinococcus radiodurans (2012). Acta Crys. D68 p.703-712.

Stelter M, Gutsche I, Kapp U, Bajic G, Goret G, Jamin M, Timmins J, Terradot L (2012). Architecture of a dodecameric bacterial replicative helicase. Structure 20 p.554-564.

Timmins J, Gordon E, Caria S, Leonard G, Monchois V and McSweeney S (2009). Structural and mutational analyses of Deinococcus radiodurans UvrA2 provide insight into DNA binding and damage recognition by UvrAs. Structure 17, 547–558.

Timmins J, Leiros I and McSweeney S (2007). Crystal structure of the RecOR complex from Deinococcus radiodurans suggests a possible mechanism for recognition of stalled replication forks. EMBO J. 26, 3260-3271.

Timmins J, Leiros I, Hall D and McSweeney S (2005). Crystal structure and DNA binding analysis of RecO from Deinococcus radiodurans. EMBO J. 24, 906-18.