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Details for article 3 of 7 found articles
| Title: |
Inhibition of nitrogenase by oxygen in marine cyanobacteria controls the global nitrogen and oxygen cycles |
| Author: |
I. Berman-Frank Y.-B. Chen Y. Gerchman G. C. Dismukes P. G. Falkowski |
| Appeared in: |
Biogeosciences discussions |
| Paging: | Volume 2 (2005) nr. 2 pages 261-273 |
| Year: |
2005 |
| Contents: |
Cyanobacterial N2-fixation supplies the vast majority of biologically accessible inorganic nitrogen to nutrient-poor aquatic ecosystems. The process, catalyzed by the heterodimeric protein complex, nitrogenase, is thought to predate that of oxygenic photosynthesis. Remarkably, while the enzyme plays such a critical role in Earth's biogeochemical cycles, the activity of nitrogenase in cyanobacteria is markedly inhibited <I>in vivo</I> at a post-translational level by the concentration of O2 in the contemporary atmosphere leading to metabolic and biogeochemical inefficiency in N2 fixation. We illustrate this crippling effect with data from <I>Trichodesmium</I> spp. an important contributor of "new nitrogen" to the world's subtropical and tropical oceans. The enzymatic inefficiency of nitrogenase imposes a major elemental taxation on diazotrophic cyanobacteria both in the costs of protein synthesis and for scarce trace elements, such as iron. This restriction has, in turn, led to a global limitation of fixed nitrogen in the contemporary oceans and provides a strong biological control on the upper bound of oxygen concentration in Earth's atmosphere. |
| Publisher: |
Copernicus GmbH (provided by DOAJ) |
| Source file: |
Elektronische Wetenschappelijke Tijdschriften |
Details for article 3 of 7 found articles
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