GDP-6-deoxy-D-talose and its 4-epimer GDP-D-rhamnose are unusual sugars found on the cell surface of certain Gram-negative bacteria. GDP-6-deoxy-talose and GDP-rhamnose are produced by enzymes called GTS and RMD, respectively. We have determined a novel X-ray crystallographic structure of RMD from Pseudomonas aeruginosa that contains its cosubstrate NADPH within the active site. Further studies will be performed to determine the structure of GTS and both enzymes will be assessed via steady state kinetics. Characterization of GTS and RMD will allow for an understanding of how bacteria utilize these sugars and may give insight into the pathogenicity of certain Gram-negative bacteria. Furthermore, an understanding of the production of unusual sugars can allow for the derivatization of existing antibiotics in an effort to combat bacterial resistance.
Faculty Mentor: Paul Cook, Chemistry