CHED 832 |
| The glutamine amidotransferase (GATase) family of biosynthetic enzymes shares in common the ability to catalyze the coordinated removal of ammonia from glutamine and subsequent transfer to a substrate to form a new carbon-nitrogen group. Exemplifying these proteins is carbamoyl phosphate synthetase—it coordinates five substrates and three intermediates between three active sites that are inter-connected via 100Ĺ of tunnels to produce carbamoyl phosphate. The reaction of ATP and bicarbonate within the first active site of the large subunit represents the rate-limiting step and the stimulus for an inter-subunit, allosteric signal promoting glutamine hydrolysis in the small subunit. The conformational changes accompanying carboxyphosphate formation at the nucleotide binding site, as well as the allosteric response manifested within the amidotransferase domain, have thus far escaped experimental characterization. In this study, we have engineered via site-directed mutagenesis a series of eight tryptophan probes potentially sensitive to these synchronizing movements. Supported by NIH-INBRE Grant #P20RR016478-04. |
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Undergraduate Research Poster Session: Biochemistry
2:00 PM-4:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster
Division of Chemical Education |