Iron conservation by reduction of metalloenzyme inventories in the marine diazotroph Crocosphaera watsonii
Name
Follows_Iron conservation.pdf
Size
2.36 MB
Format
Adobe PDF
Checksum (MD5)
dc4e0fcce9fd8fd1ff76362cd7498401
Author(s)
Saito, Mak A.
Bertrand, Erin M.
Dutkiewicz, Stephanie
Bulygin, Vladimir V.
Moran, Dawn M.
Monteiro, Fanny Meline
Valois, Frederica W.
Waterbury, John B.
Follows, Michael J
Date Issued
January 2011
Journal
Proceedings of the National Academy of Sciences
Publisher
National Academy of Sciences (U.S.)
Citation
Saito, M. A., E. M. Bertrand, S. Dutkiewicz, V. V. Bulygin, D. M. Moran, F. M. Monteiro, M. J. Follows, F. W. Valois, and J. B. Waterbury. “Iron Conservation by Reduction of Metalloenzyme Inventories in the Marine Diazotroph Crocosphaera Watsonii.” Proceedings of the National Academy of Sciences 108, no. 6 (January 19, 2011): 2184–2189.
Version
Final published version
Abstract
The marine nitrogen fixing microorganisms (diazotrophs) are a major source of nitrogen to open ocean ecosystems and are predicted to be limited by iron in most marine environments. Here we use global and targeted proteomic analyses on a key unicellular marine diazotroph Crocosphaera watsonii to reveal large scale diel changes in its proteome, including substantial variations in concentrations of iron metalloproteins involved in nitrogen fixation and photosynthesis, as well as nocturnal flavodoxin production. The daily synthesis and degradation of enzymes in coordination with their utilization results in a lowered cellular metalloenzyme inventory that requires ~40% less iron than if these enzymes were maintained throughout the diel cycle. This strategy is energetically expensive, but appears to serve as an important adaptation for confronting the iron scarcity of the open oceans. A global numerical model of ocean circulation, biogeochemistry and ecosystems suggests that Crocosphaera’s ability to reduce its iron-metalloenzyme inventory provides two advantages: It allows Crocosphaera to inhabit regions lower in iron and allows the same iron supply to support higher Crocosphaera biomass and nitrogen fixation than if they did not have this reduced iron requirement.
MIT Department
Massachusetts Institute of Technology. Center for Global Change Science
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1073/pnas.1006943108
