Genetic mapping of pDS15 revealed that this cosmid clone carries the Sinorhizobium meliloti TCA cycle genes mdh, sucCDAB, sdhAB and part of lpdA. Three genes (mdh, sucC , and sucA) were completely sequenced and submitted to GenBank. The nucleotide and amino acid sequences of the TCA cycle genes encoded on pDS15 were aligned and found to be highly homologous with other closely related rhizobial species. S. meliloti cells grown in LBmc express the mdh-sucCDAB operon as one transcript, based on RT-PCR results. Alternative sigma factor sigma54 was not found to have a role in mdh-sucCDAB expression. Despite considerable effort, we have not been able to isolate sucA mutants via random transposon Tn5tac1 mutagenesis to date. Homologous recombination between a plasmid-borne sucA::Tn5 and wild-type S. meliloti sucA failed to generate a bona fide mutant, as revealed by Southern blot analysis. Plasmid pDS15 was mutagenized with transposons Tn5, Tn5tac1, and Tn5-B20. Three Tn5-B20 insertions were mapped to mdh, sucD, and sucA respectively, and preliminary gene expression studies were done.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.33808 |
| Date | January 2001 |
| Creators | Meek, David J. J. |
| Contributors | Driscoll, Brian T. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Natural Resource Sciences.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001872493, proquestno: MQ78925, Theses scanned by UMI/ProQuest. |
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