CHED 954 |
| Site-specific incorporation of fluorinated amino acids using altered translational machinery provides access to detailed studies on protein conformational changes. Nitrogen Regulatory Protein C (NtrC), a positively acting bacterial transcription factor, makes up one unit of a two component regulatory system. The other unit, a sensor histidine kinase, phosphorylates the D54 residue in the amino (N)-terminal domain of NtrC in response to changes in nitrogen concentration. The receiver domain of NtrC is thus activated by phosphorylation and sends a signal to the NtrC transcriptional activator domain via structural rearrangements. In this study, para-trifluoromethylphenylalanine (TFM) was introduced site-specifically into NtrC, in vivo, with an altered tRNA/aminoacyl-tRNA synthetase pair. TFM was site-specifically inserted in response to the TAG nonsense codon at sites 5, 66, 94, 99, and 101 to produce NtrC variants that could be monitored by 19F NMR. By monitoring the chemical shifts of the 19F signal from labeled NtrC variants the conformational changes/structural rearrangements taking place in response to varying levels of nitrogen can be investigated. |
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Undergraduate Research Poster Session: Biochemistry
2:00 PM-4:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Chemical Education |