|BS||Kent State University||Kent, Ohio||Chemistry|
|PhD||Johns Hopkins School of Medicine||Baltimore, Md.||Biochemistry|
Our laboratory studies the three-dimensional structures of proteins relevant to human disease. A major focus of the lab is characterizing proteins in an enzyme superfamily known as the alpha-D-phosphohexomutases. These enzymes catalyze the production of phosphorylated sugar precursors that are assembled into more complex carbohydrates, such as polysaccharides. Enzymes in this superfamily are found in all organisms, including bacteria, archaea, and eukaryotes. In many bacteria, polysaccharides are critical determinants of infectivity, and so these enzymes are excellent targets for the design of antimicrobial agents. In humans, deficiency in the enzyme phosphoglucomutase 1 (PGM1) has been recently identified as an inherited metabolic disease categorized as both a muscle glycogenosis (type XIV) and a congenital disorder of glycosylation (CDG types I and II).
In studies of the bacterial members of the superfamily, we have conducted detailed structure-function analyses using methods including X-ray crystallography, kinetics, small angle X-ray scattering, and hydrogen deuterium exchange. These studies include enzymes from important human pathogens, including P. aeruginosa, B. anthracis, and S. typhimurium. We have also utilized computational analyses, such as normal mode and co-evolutionary analyses to better understand the relationships between protein structure, conformational flexibility, and sequence relationships in the family. In collaboration with the laboratory of Steven Van Doren, we are characterizing the role of protein dynamics in the mechanism of P. aeruginosa PMM/PGM via NMR. Insights from our recent studies include a key role for phosphorylation of the active site serine in both catalysis and enzyme flexibility. Our recent work on human PGM1 includes biochemical and structural characterization of missense variants associated with disease. A better understanding of the molecular bases of this inherited disease should benefit patient prognosis and therapy.
Compromised catalysis and potential folding defects in in vitro studies of missense mutants associated with hereditary phosphoglucomutase 1 deficiency. Lee Y, Stiers KM, Kain BN, Beamer LJ. J Biol Chem. 2014 Oct 6. pii: jbc.M114.597914. [Epub ahead of print]
Beamer LJ. Mutations in hereditary phosphoglucomutase 1 deficiency map to key regions of enzyme structure and function. J Inherit Metab Dis. 2014 Aug 29. [Epub ahead of print].
Lee Y, Villar MT, Artigues A, Beamer LJ. Promotion of enzyme flexibility by dephosphorylation and coupling to the catalytic mechanism of a phosphohexomutase. J Biol Chem. 289(8):4674-82 (2014).
Yingying Lee, Ritcha Mehra-Chaudhary, Cristina Furdui, and Lesa J. Beamer. Identification of an essential active site residue in the a-D-phosphohexomutase superfamily. FEBS J. 280(11):2622-32 (2013).
Emily K. Luebbering, Jacob Mick, Ranjan Singh, John J. Tanner, Ritcha Mehra-Chaudhary and Lesa J. Beamer. Evolutionary conservation of global motions in an enzyme superfamily across varying quaternary structures. J Mol Biol. 423: 831-46 (2012).
Yingying Lee, Jacob Mick, Cristina Furdui, and Lesa J. Beamer. A coevolutionary residue network at the site of a functionally important conformational change in a phosphohexomutase enzyme family. PLOS One. 7(6): e38114. (2012).
Akella V.S. Sarma, Asokan Anbanandam, Allek Kelm, Yirui Wei, Ritcha Mehra-Chaudhary, Mark V. Berjanskii, Jacob A. Mick, Lesa J. Beamer and Steven R. Van Doren. Intrinsic Mobility, Phosphoryl Transfer Defect, and Structure of the 463-Residue Reversible Enzyme, Phosphohexomutase. Biochemistry. 51(3):807-19 (2012).
Ritcha Mehra-Chaudhary, Jacob Mick, John J. Tanner, and Lesa J. Beamer. Quaternary structure, conformational variability, and global motions of phosphoglucosamine mutase. FEBS J. 278 (18): 3298-3307 (2011).
Ritcha Mehra-Chaudhary, Jacob Mick and Lesa J. Beamer. Crystal structure of phosphoglucosamine mutase from B. anthracis, an enzyme in the peptidoglycan biosynthetic pathway. J. Bacteriology. 193 (16): 4081-7 (2011).
Ritcha Mehra-Chaudhary, Jacob Mick, John J. Tanner, Michael T. Henzl, and Lesa J. Beamer. Crystal structure of a bacterial phosphoglucomutase, an enzyme involved in the virulence of multiple human pathogens. PROTEINS: Structure, function, and bioinformatics. 79 (4): 1215-29 (2011).
Andrew M. Schramm, Dale Karr, Ritcha Mehra-Chaudhary, Steven R. Van Doren, Cristina M. Furdui, Lesa J. Beamer. Breaking the covalent connection: Chain connectivity and the catalytic reaction of PMM/PGM. Protein Science. 19:1235-1242 (2010).
Research areas: Structural biology: X-ray crystallography of medically important proteins.
How to apply:
Electronic submission is encouraged, e-mail to firstname.lastname@example.org
Applicants should send CV and names of two references to:
Dr. Lesa J. Beamer
117 Schweitzer Hall
University of Missouri
Columbia, MO 65211