Mutants of Anabaena variabilis requiring high levels of molybdate for nitrate reductase and nitrogenase activities
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منابع مشابه
Alternative Nitrogenases in Anabaena variabilis: The Role of Molybdate and Vanadate in Nitrogenase Gene
Anabaena variabilis ATCC 29413 has two distinct nitrogenases that function in heterocysts, a conventional Mo-nitrogenase and an alternative V-nitrogenase. Synthesis of these two enzymes was repressed in cells growing with a source of fixed nitrogen, such as ammonium; however, the V-nitrogenase was also repressed by Mo. Expression of the V-nitrogenase which was not affected by V and expression o...
متن کاملMolybdate transport and its effect on nitrogen utilization in the cyanobacterium Anabaena variabilis ATCC 29413.
Molybdenum is an essential component of the cofactors of many metalloenzymes including nitrate reductase and Mo-nitrogenase. The cyanobacterium Anabaena variabilis ATCC 29413 uses nitrate and atmospheric N2 as sources of nitrogen for growth. Two of the three nitrogenases in this strain are Mo-dependent enzymes, as is nitrate reductase; thus, transport of molybdate is important for growth of thi...
متن کاملRNA processing of nitrogenase transcripts in the cyanobacterium Anabaena variabilis.
Little is known about the regulation of nitrogenase genes in cyanobacteria. Transcription of the nifH1 and vnfH genes, encoding dinitrogenase reductases for the heterocyst-specific Mo-nitrogenase and the alternative V-nitrogenase, respectively, was studied by using a lacZ reporter. Despite evidence for a transcription start site just upstream of nifH1 and vnfH, promoter fragments that included ...
متن کاملCharacterization of genes for a second Mo-dependent nitrogenase in the cyanobacterium Anabaena variabilis.
Anabaena variabilis ATCC 29413 is a filamentous heterocystous cyanobacterium that fixes nitrogen under a variety of environmental conditions. Under aerobic growth conditions, nitrogen fixation depends upon differentiation of heterocysts and expression of either a Mo-dependent nitrogenase or a V-dependent nitrogenase in those specialized cells. Under anaerobic conditions, a second Mo-dependent n...
متن کاملCharacterization of genes for an alternative nitrogenase in the cyanobacterium Anabaena variabilis.
Anabaena variabilis ATCC 29413 is a heterotrophic, nitrogen-fixing cyanobacterium that has been reported to fix nitrogen and reduce acetylene to ethane in the absence of molybdenum. DNA from this strain hybridized well at low stringency to the nitrogenase 2 (vnfDGK) genes of Azotobacter vinelandii. The hybridizing region was cloned from a lambda EMBL3 genomic library of A. variabilis, mapped, a...
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ژورنال
عنوان ژورنال: FEMS Microbiology Letters
سال: 1990
ISSN: 0378-1097
DOI: 10.1111/j.1574-6968.1990.tb13825.x