An enzyme for nucleotide sugar modification in A. Baumannii

The gram-negative bacillus Acinetobacter baumannii is an emerging multidrug-resistant, opportunistic pathogen responsible for severe nosocomial and community pneumonia outbreaks worldwide. Increasing resistance to antibiotics is thought to be due in part to highly variable genomic islands and lateral gene transfer. To date there have been studies into multiple genes in A. baumannii that are thought to play major roles in its resistance capabilities. One such gene found in a genomic island of the D1279779 strain of A. baumannii, fnIA, encodes for the protein Ab-WbjB, an extended short-chain dehydrogenase/reductase (SDR). Although it is similar in structure to other members of the SDR family, little is known about its function in A. baumannii. I have carried out analysis on the active site chemistry of Ab-WbjB, discovering the necessity for the presence of its cofactor NADP for both overall protein stability and substrate binding. I have also found that Ab-WbjB binds to the substrate analogue UDP-GlcNAc. In addition to functional assays of the protein, an attempt at crystal growth was made under conditions containing both NADP and UDP-GlcNAc. A knockout of the fnlA gene in A. baumannii was also planned, but has yet to be completed.