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http://hdl.handle.net/11375/23544
Title: | Phosphoenolpyruvate Carboxykinase (PCK) Gene Regulation in Sinorhizobium Meliloti |
Other Titles: | PCK Gene Regulation in S. Meliloti |
Authors: | O'Brien, Shelley |
Advisor: | Finan, T. M. |
Department: | Biology |
Keywords: | phosphoenolpyruvate carboxykinase;gene regulation;sinorhizobium meliloti |
Publication Date: | Dec-1998 |
Abstract: | Phosphoenolpyruvate carboxykinase (Pck) catalyzes the first step of gluconeogenesis, and the gene which encodes this enzyme (pckA) is transcriptionally regulated. High pckA expression is observed in succinate-grown cells, while little expression is observed in glucose-grown cells. pckA regulatory mutants have previously been isolated (Osteras et al. 1997) and pckR, a gene encoding a Lacl-GaIR DNA-binding transcriptional regulator, has been implicated in the regulation of pckA transcription. Here we shew that pckR insertion mutations result in a dramatic decrease in pckA expression even in succinate-grown cells. We demonstrate that the previously identified rpk-9 mutation is tightly linked to pckR. The rpk-9 mutation results in constitutive pckA expression, and we show that plasmids carrying the pckR gene complement the rpk-9 mutation in glucose-grown cells. A putative Lacl-GaIR operator binding site has been identified in the pckA promoter, however no evidence of an interaction between this site and the pckR gene product could be found. |
URI: | http://hdl.handle.net/11375/23544 |
Appears in Collections: | Digitized Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
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o'brien_shelley_a_p_1998Dec_masters.pdf | 6.12 MB | Adobe PDF | View/Open |
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