Xin Sun 56 Gardener Street Apt 8, Allston, MA 02134 Phone: 781-296-7882 (Cell) Email:
[email protected] EDUCATION Brandeis University, Waltham, MA, 2005 – 2011 Ph.D. in Biochemistry Advisor: Lizbeth Hedstrom University of California, Berkeley, Berkeley, CA, 2001 - 2005 B.A. in Molecular and Cell Biology, Division of Biochemistry and Molecular Biology RESEARCH SUMMARY Boston University, Boston, MA, 2011 – present Moenomycin A (MmA) is the prototypical phosphoglycolipid antibiotic produced by Streptomyces spp. and is the only known active site inhibitor of the peptidoglycan glycosyltransferases (PGT) , the bacterial cell wall sugar polymerases. A mechanistically intriguing methylation of an sp3-hybridized carbon occurs during MmA biosynthesis; this reaction is catalyzed by MoeK5, a cobalamin radical-SAM methyltransferase, but the mechanism is not understood. My work has focused on the expression, purification, and reconstitution of MoeK5 with its two complex metal cofactors, methylcobalamin and an iron-sulfur cluster. Furthermore, biochemical analysis of MmA production demonstrates that methylation occurs early in the MmA biosynthetic pathway. Using MmA biosynthetic enzymes, I have chemo-enzymatically synthesized the likely MoeK5 sugar-lipid substrate. I am currently poised to carry out a detailed mechanistic study of this elusive class of enzymes. Brandeis University, Waltham, MA, 2005 – 2011 Cryptosporidium parvum is a eukaryotic, disease causing human pathogen for which there are no vaccines or drugs available. Genomic analysis suggests the parasite is almost entirely dependent on salvage pathways for the synthesis of metabolites. In my research, I enzymatically characterized one of the parasite’s pyrimidine salvage enzymes, thymidine kinase, and assessed its role both as a potential drug target and in the activation of prodrugs.