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http://hdl.handle.net/11375/15964
Title: | L-Hydroxyproline and D-Proline Catabolism in Sinorhizobium meliloti |
Authors: | Chen, Siyun |
Advisor: | Finan, Turlough |
Department: | Chemical Biology |
Keywords: | L-Hydroxyproline, D-Proline |
Publication Date: | Nov-2014 |
Abstract: | Hydroxyproline as a modified amino acid can serve as a carbon and nitrogen source for certain microorganisms. Its primary isomer trans-4-hydroxy-L-proline is found in the root nodule of legume plants. Hydroxyproline (Hyp) catabolism has been characterized in bacteria and animal cells. In bacteria, trans-4-hydroxy-L-proline (trans-4-L-proline) is converted to the central metabolite α-ketoglutarate (α-KG) by four reactions. The Hyp catabolism pathway has been identified in the nitrogen-fixing legume endosymbiont Sinorhizobium meliloti. hypS is one of the transcripts in the 14 hyp gene cluster on the pSymB megaplasmid, and was annotated to encode a putative malate/L-lactate dehydrogenase. In this study, purified HypS was assayed on different substrates and the reaction products were characterized. It was demonstrated that HypS can oxidize L-proline and reduce Δ1-pyrroline-2-carboxylate, but not on L-malate. Noticeably unlike the wild type strain, a hypS- mutant strain failed to grow on D-proline. The ability of D-proline to support grow of an L-proline auxotroph, together with the substrate specificity of HypS, strongly suggests that hypS is involved in the metabolism of D-proline to L-proline in S. meliloti. The possible role of HypS in the catabolism of Hyp or related compounds remains to be determined. |
URI: | http://hdl.handle.net/11375/15964 |
Appears in Collections: | Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
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MSc thesis -Siyun Chen - 1252553.pdf | M.Sc thesis - Siyun Chen - 1252553 | 2.71 MB | Adobe PDF | View/Open |
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