Dale Poulter
John A. Widtsoe Distinguished Professor of Chemistry and Professor of Biochemistry
B.S. Louisiana State University
Ph.D. University of California, Berkeley
Dale Poulter's Lab Page
Dale Poulter's PubMed Literature Search
Research
My research group studies how biosynthetic pathways emerge through the evolution of new enzyme activities. We use a variety of biochemical, microbiological, and molecular biological techniques to determine structure-function relationships, with a special emphasis on understanding how the active sites of enzymes can be molded to efficiently synthesize new compounds. Our interests include enzymes in the isoprene synthase superfamily, which are responsible for synthesis of over 60,000 naturally occurring molecules, the independently evolved mevalonate and methylerythritol phosphate pathways for synthesis of the isoprenoid building blocks, and the enzymes that attach isoprenoid units to non-isoprenoid acceptors in the posttranscriptional modification of tRNA, the posttranslational modification of proteins, and the biosynthesis of amino acid and quinoid metabolites.
Enzymes in the isoprene synthase superfamily catalyze the eight basic bond-forming reactions to construct the carbon skeletons of metabolites in the isoprenoid pathway, each with high selectivity for a specific reaction. These molecules are essential for life and the pathway is found in all organisms. Our structure-function studies show that the high selectivity of isoprene synthases can be altered by mutagenesis to give enzymes that produce products with all but one of the carbon skeletons formed in nature and provide insight about how new enzyme activities can be developed from a parental protein scaffold.
Eukaryota and Archaea synthesize isoprenoid molecules from acetyl CoA by the mevalonate pathway. However the genomes of Archaea lack two of the enzymes found in eukaryotes. We have characterized the kinetic properties and determined the X-ray structure of one of the missing enzymes and are working to discover the missing the gene for the missing enzyme. Our work has led to the discovery new biosynthetic enzymes and an understanding of how they are related to other members of the isoprenoid synthase superfamily. We are currently using genome screening, biochemical characterization and structural methods to understand the evolutionary relationships in this group of enzymes.
References
1. Mabanglo MF, Schubert HL, Chen M, Hill CP, Poulter CD (2010) X-ray structures of isopentenyl phosphate kinase. Chem Biol, In Press
2. Chen M, Poulter CD (2010) Characterization of Thermophilic Archaeal Isopentenyl Phosphate Kinases. Biochemistry 49:207-217
3. Pan J-J, Bugni TS, Poulter CD (2009) Recombinant Squalene Synthase. Synthesis of Cyclopentyl Non-Head-to-Tail Triterpenes. J Org Chem 74:7562-7565
4. Poulter CD (2009) Bioorganic Chemistry. A Natural Reunion of the Physical and Life Sciences. J Org Chem 74:2631-2645
5. de Ruyck J, Pouyez J, Rothman SC, Poulter CD, Wouters J (2008) Crystal Structure of Type 2 Isopentenyl Diphosphate Isomerase from Thermus thermophilus in Complex with Inorganic Pyrophosphate. Biochemistry 47:9051-9053
6. Lee S, Poulter CD (2008) Cloning, Solubilization, and Characterization of Squalene Synthase from Thermosynechococcus elongates BP-1. J Bacteriol 190:3808-3816
7. Rothman SC, Johnston JB, Lee S, Walker JR, Poulter CD (2008) Type II Isopentenyl Diphosphate Isomerase: Irreversible Inactivation by Covalent Modification of Flavin. J Am Chem Soc 130:4906-4913
8. Thulasiram HV, Erickson HK, Poulter CD (2008) A Common Mechanism for Branching, Cyclopropanation, and Cyclobutanation Reactions in the Isoprenoid Biosynthetic Pathway. J Am Chem Soc 130:1966-1971
9. Thulasiram HV, Erickson HK, Poulter CD (2007) Chimeras of Two Isoprenoid Synthases Catalyze all Four Coupling Reactions in Isoprenoid Biosynthesis. Science 316:73-76
10. Johnston JB, Walker JR, Rothman SC, Poulter CD (2007) Type-2 Isopentenyl Diphosphate Isomerase. Mechanistic Studies with Cyclopropyl and Epoxy Analogs. J Am Chem Soc 129:7740-7741
11. Lee S, Poulter CD (2006) Escherichia coli Type I Isopentenyl Diphosphate Isomerase: Structural and Catalytic Roles for Divalent Metals. J. Am. Chem. Soc. 128:11545-11550
2. Gauchet C, Labadie GR, Poulter CD (2006)Regio- and Chemoselective Covalent Immobilization of Proteins through Unnatural Amino Acids. J. Am. Chem. Soc. 128:9274-9275
3. Thulasiram HV, Phan RM, Rivera SB, Poulter CD (2006)Synthesis of Deuterium Labeled Derivatives of Dimethylallyl Diphosphate. J. Org. Chem. 71:1739-1741
4. Lherbet C, Pojer F, Richard SB, Noel JP, Poulter CD (2006)Absence of Substrate Channeling between Active Sites in the Agrobacterium tumefaciens IspDF and IspE Enzymes of the Methyl Erythritol Phosphate Pathway. Biochemistry 45:3548-3553
5. Cornish RM, Roth JR, Poulter CD (2006)Lethal mutations in the isoprenoid pathway of Salmonella enterica. J. Bacteriol. 188:1444-1450
6. Testa CA, Lherbet C, Pojer F, Noel JP, Poulter CD (2006)Cloning and Expression of IspDF from Mesorhizobium loti. Characterization of a Bifunctional Protein that Catalyzes Non-Consecutive Steps in the Methylerythritol Phosphate Pathway. Biochem. Biophys. Acta, 1764:85-96
7. Poulter CD (2006)Farnesyl Diphosphate Synthase. A Paradigm for Understanding Structure and Function Relationships in E-Polyprenyl Diphosphate Synthases” Phytochem. Reviews 5:17-26
8. Wu Z, Wouters J, Pouter CD (2005)Isopentenyl Diphosphate Isomerase. Mechanism-Based Inhibition by Diene Analogues of Isopentenyl Diphosphate and Dimethylallyl Diphosphte. J. Am. Chem. Soc. 127:17433-17438
9. Walker JR, Poulter CD (2005)Synthesis and Evaluation of 1-Deoxy-D-xylulose 5-Phosphate Analogs as Chelation Based Inhibitors of Methylerythritol Phosphate Synthase. J. Org. Chem. 70:9955-9959
10. de Ruyck J, Rothman SC, Poulter CD, Wouters J (2005)Structure of Thermus thermophilus type 2 isopentenyl diphosphates isomerase inferred from crystallography and molecular dynamics. Biochem. and Biophys. Res. Comm. 338:1515–1518
11. Fox DT, Poulter CD (2005)Mechanistic Studies with 2C-Methyl-D-erythritol 4-Phosphate Synthase from Escherichia coli. Biochemistry 44:8360-8368
12. Fox DT, Poulter CD (2005)Synthesis and Evaluation of 1-Deoxy-D-xylulose 5-Phosphoric Acid Analogs as Alternate Substrates for Methylerythritol Phosphate Synthase. J. Org. Chem. 70:1978-1985
Updated 8/15/2010
