Nitrogenase genes

X, N, Ep and H are needed for synthesis of FeMo-co and for its incorporation into the MoFe-protein.55/55a Nif A is an activator gene for the whole duster including the nifL gene product, which is altered by the presence of 02 or of glutamine. Accumulation of the latter in cells (see Section B,2) strongly represses transcription of the nitrogenase genes. 

Yet another enzyme able to release or transfer sulfur in the S° oxidation state is the PLP-dependent cysteine desulfurase that is encoded by the nifS gene of the nitrogenase gene cluster shown in Fig. 24-4. 

Chen, Y. B., Mellon, M. T., and Zehr, J. P. (1998). Circadian rhythm of nitrogenase gene expression in the diazotrophic filamentous nonheterocystous cyanobacterium Trichodesmium sp. Strain IMS 101. Bacteriol. 180, 3598—3605. 

Mehta, M., Huber, J., and Baross, J. (2005). Incidence of novel and potentially archaeal nitrogenase genes in the deep Northeast Pacific Ocean. Environ. Microbiol. 7, 1525—1534. 

Zehr,J. P., Jenkins, B. D., etal. (2003). Nitrogenase gene diversity and microbial community structure a cross-system comparison. Environ. Microbiol. 5, 539—554. 

Zehr, J. P., et al. (2007). Experiments linking nitrogenase gene expression to nitrogen fixation in the North Pacific subtropical gyre. Limnol. Oceanogr. 52, 169—183. 

Zehr, J. P., Montoya, J. P., Jenkins, B. D., Hewson, I., Mondragon, E., Short, C. M., Church, M. J., Hansen, A., and Karl, D. M. (2007). Experiments linking nitrogenase gene expression to nitrogen fixation in the North Pacific subtropical gyre. Limnol. Oceanogr. 52, 169—183. 

Wyman, M., Zehr, J. P., and Capone, D. G. (1996). Temporal variability in nitrogenase gene expression in the diazotrophic filamentous non-heterocystous cyanobacterium Trichodesmium thie-bautii. Appl. Environ. Microbiol. 62, 1073—1075. 

AfFourtit, J. (1997). Characterization and quantitation of nitrogenase genes along a salinity gradient in the Neuse River, Rensselaer Polytechnic Institute. 

Hennecke H, Kaluza K, Thtiy B, Fuhrmann M, Ludwig W, Stsckebrandt E. (1985). Concurrent evolution of nitrogenase genes and 16S rRNA Rhizobium species and other nitrogen fixing bacteria. Arch. Microbiol. 142, 342-348. 

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