A requirement for phosphoenolpyruvate carboxylase in the cyanobacterium Synechococcus PCC 7942
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The gene encoding phosphoenolpyruvate carboxylase (PEPCase) in the cyanobacterium Synechococcus PCC 7942 has been isolated and characterized. As a first step in determining the role of this enzyme in cyanobacterial carbon metabolism we have attempted to generate PEPCase deficient mutants by insertional inactivation of the PEPCase gene (ppc) and recombination into the wild-type genome. Transformants generated by these constructs appear to be merodiploids in which some copies of ppc remain intact and PEPCase activity is present. Successful insertional inactivation of regions of the genome on either side of ppc suggest that the merodiploid state is a result of a requirement for PEPCase activity by the cyanobacteria. Attempts to select for ppc mutants by nutritional complementation during segregation are also described.
Key wordsCyanobacteria Synechocccus PEPCase gene inactivation merodiploid carbon metabolism
gene coding for PEPCase
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- Coleman JR, Colman B (1981) Photosynthetic carbon assimilation in the blue-green algae, Coccochloris peniocystis. Plant Cell Environ 4: 285–290Google Scholar
- Ishijima S, Katagiri F, Kodaki T, Izui K, Katsuki H, Nishikawa K, Nakashima H, Ooi T (1985) Comparison of amino acid sequences between phosphoenolpyruvate carboxylases from Escherichia coli and Anacystis nidulans: identification of conserved and variable regions. Biochem Biophys Res Commun 133: 436–441CrossRefGoogle Scholar
- Maniatis T, Fritsch E, Sambrook J (1982) Molecular cloning: A laboratory manual. Cold Spring Harbor Laboratory, Cold Spring HarborGoogle Scholar
- Maruyama H, Easterday RL, Chang HC, Lane MD (1986) The enzymatic carboxylation of phosphoenolpyruvate. I. Purification and properties of phosphoenolpyruvate carboxylase. J Biol Chem 241: 2405–2412Google Scholar