Sylvie Doublié, Ph.D.
Associate Professor of Microbiology and Molecular Genetics
Research Program: Genome Stability & Expression
VCC Membership Level: Full Member
Contact Information
E314A Given Building
89 Beaumont Avenue
University of Vermont
Burlington, VT 05405
ph: (802) 656-9531
f: (802) 656-8749
Sylvie.Doublie@uvm.edu
Biography
Dr. Doublié received her Ph.D. in biochemistry and biophysics in 1993, under the direction of Charles W. Carter at the University of North Carolina at Chapel Hill. She did postdoctoral work with Stephen Cusack at the European Molecular Biology Laboratory outstation in Grenoble, France, and with Dr. Tom Ellenberger at Harvard Medical School, where she solved the crystal structure of the ternary complex of T7 DNA polymerase. She joined the UVM faculty in October 1998. In 2000, Dr. Doublié was one of twenty scientists to win the prestigious Pew Scholars Program in the Biomedical Sciences Award.
Research
Modifications in DNA or RNA, as part of normal cellular processes or as aberrations, can have profound biological consequences. The major thrust of my research program is to study these nucleic acid modifications in the context of the enzymes and proteins that generate and recognize them.
DNA polymerases, which otherwise faithfully replicate DNA, stumble when they encounter oxidative DNA lesions. Polymerases either will be blocked at the site of lesion, or bypass it. The latter case, referred to as translesion synthesis, may initiate an oncogenic process if the wrong base is inserted opposite the lesion. Uncovering the fundamental mechanisms underpinning translesion synthesis is paramount to understand the initial events of mutagenesis. We aim to elucidate at the atomic level the factors that influence the interactions between a replicative polymerase and DNA lesions. Our goal is to answer the following questions: How does a DNA polymerase sense the presence of a DNA lesion? What role does sequence context play in translesion synthesis? What triggers the transfer of DNA to the editing site in the event of a base mispair?
Several DNA repair mechanisms are in place to minimize damage in DNA before DNA polymerases replicate the genome. One of these processes is called Base Excision Repair (BER). The first step in BER is carried out by DNA glycosylases, so named because they hydrolyze the N-glycosidic bond between a damaged base and its deoxyribose, leaving an apurinic or apyrimidinic site in DNA. The goal of this project is to delineate the structural features of the DNA glycosylases that are involved in recognition of DNA base damage produced by ionizing radiation. In particular, we intend to address the question of how enzymes with a similar active site architecture are able to recognize vastly different substrates.
Messenger RNA (mRNA) also undergoes modifications, this time as an essential step of the normal cell program. During processing of the 3'-end of mRNA, a specific endonucleolytic cleavage event precedes the addition of a poly(A) tail. Such maturation of 3'-ends is a key regulatory step in the expression of many genes. The cleavage and polyadenylation reactions are carried out by a multicomponent machinery of remarkable complexity. Our goal is to understand how the different components of the machinery interact to cleave then polyadenylate messenger RNAs.
Recent Publications
Coseno M, Martin G, Berger C, Gilmartin G, Keller W, Doublié S. (2008) Crystal Structure of the 25 kDa Subunit of Human Cleavage Factor Im. Nucleic Acids Research 36:3474-83. PMCID: PMC2425470
Martin G, Doublié S, Keller W. (2008) Determinants of substrate specificity in RNA-dependent nucleotidyl transferases. Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression. 1779:206-16.
Hogg M, Aller P, Konigsberg W, Wallace SS, Doublié S. (2007) Structural and biochemical investigation of the role in proofreading of a β hairpin loop found in the exonuclease domain of a replicative DNA polymerase of the B family J. Biol. Chem. 282:1432-1444.
Aller P, Rould MA, Hogg M, Wallace SS, Doublié S. (2007) A structural rationale for stalling of a replicative DNA polymerase at the most common oxidative thymine lesion, thymine glycol. PNAS 104:814-818. PMCID: PMC1783396
Zahn KE, Belrhali H, Wallace SS, Doublié S. (2007) Caught Bending the A-Rule: Crystal Structures of Translesion DNA Synthesis with a non natural nucleotide. Biochemistry 46:10551-61
Hogg M, Wallace SS, Doublié S. (2005) Bumps in the road: how replicative DNA polymerases see DNA damage. Curr Opin Struct Biol. 15:86-93.
Hogg M, Wallace SS, Doublié S. (2004) Crystallographic snapshots of a replicative DNA polymerase encountering an abasic site EMBO J. 23:1483-1493. PMCID: PMC391061
Doublié S, Bandaru V, Bond JP, Wallace SS. (2004) The crystal structure of human NEIL1 reveals a novel DNA binding motif required for glycosylase activity. PNAS 101:10284-10289. PMCID: PMC478564
Martin G, Möglich A, Keller W., Doublié S. (2004) Biochemical and Structural Insights into Substrate Binding and Catalytic Mechanism of Mammalian Poly(A) Polymerase. J. Mol. Biol. 341:911-925.
