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Enzymatic Characterization Of The Ammonia Tunnel In Helicobacter Pylori Asp-Trnaasn/Glu-Trnagln Amidotransferase, Liangjun Zhao

Wayne State University Dissertations

The Helicobacter pylori (H. pylori) Asp-tRNA^Asn/Glu-tRNA^Gln amidotransferase (AdT) plays important roles in indirect aminoacylation and translational fidelity; however, its inter-domain communication and ammonia delivery mechanisms are not well understood. In the present study, we investigated the three activities of H. pylori AdT (glutaminase, kinase and transamidase) and used these reactions as probes to examine the inter-domain communication and ammonia delivery mechanisms between this enzyme's two isolated active sites. We adapted and optimized an assay to kinetically characterize a series of mutations at conserved positions throughout the putative AdT ammonia tunnel. The kinase assay enabled us …