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Grants List


Courtesy of Mak Saito - idealized representation of a marine algal cell acquiring the cobalt-containing vitamin B12 using a  recently discovered protein named CBA1

Woods Hole Oceanographic Institution

Metalloenzymes as indicators of ocean biogeochemical processes

To enable a greater understanding of trace metals and metalloenzymes in oceanic biogeochemical cycles. By combining cutting-edge proteomic tools with trace metal analysis techniques, this project aims to advance the understanding of biogeochemical cycles by identifying and quantifying the abundance of key microbial metalloenzymes in oxygen minimum zones concurrently with trace metal analyses.

Title: Metalloenzymes as indicators of ocean biogeochemical processes
Date Awarded: Nov 2010
Amount: $1,125,081
Term: 36 months
Grant ID: GBMF2724
Funding Area: Science, Marine Microbiology Initiative



Metalloenzymes catalyze key biogeochemical reactions that allow life to sustain itself on Earth. In the marine environment, microbial communities produce the metalloenzymes that influence carbon cycling, nitrogen cycling, and organic matter degradation, for example. Yet the oceans are extraordinarily depleted in many biologically important metals: iron, cobalt, nickel, copper, and zinc are found at nanomolar or lower concentrations in surface waters. Due to the analytical challenges associated with these low abundances, our understanding of how the scarcity of metals affects metalloenzyme biosynthesis and the corresponding biogeochemical cycles is in its infancy. Important questions have yet to be answered: what are the distributions of key metalloenzymes and their microbial hosts? How are metalloenzyme distributions governed by metal and oxygen distributions? How do those abundances affect biogeochemical processes such as primary production, denitrification, and carbon remineralization? How will climate change affect many biogeochemical processes catalyzed by metalloenzymes?

In this project we are applying cutting-edge proteomic technology towards experiments on biogeochemically relevant microbial isolates under varying environmental conditions and the development of a quantitative field metalloenzyme capability to explore the distribution of these proteins and their relationships to biological and chemical features.

Read more:

Aguirre, J. D., H. M. Clark, M. McIlvin, C. Vazquez, S. L. Palmere, D. J. Grab, J. Seshu, P. J. Hart, M. Saito, & V. C. Culotta. (2013). A manganese-rich environment supports superoxide dismutase activity in a Lyme disease pathogen, Borrelia burgdorferi. J Biol Chem, 288(12), 8468-8478. doi: 10.1074/jbc.M112.433540

Bertrand, E. M., A. E. Allen, C. L. Dupont, T. M. Norden-Krichmar, J. Bai, R. E. Valas, & M. A. Saito. (2012). Influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein. Proc Natl Acad Sci U S A, 109(26), E1762-1771. doi: 10.1073/pnas.1201731109

Bertrand, E. M., D. M. Moran, M. McIlvin, J. M. Hoffman, A. E. Allen, & M. A. Saito. (2013). Methionine synthase interreplacement in diatom cultures and communities: Implications for the persistence of B12 use by eukaryotic phytoplankton. Limnol Oceanogr, 58(4), 1431-1450. doi:10.4319/lo.2013.58.4.143

Cox, A. D., & M. A. Saito. (2013). Proteomic responses of oceanic Synechococcus WH8102 to phosphate and zinc scarcity and cadmium additions. Front Microbiol, 4, 387.  doi: 10.3389/fmicb.2013.00387

Dyhrman, S. T., B. D. Jenkins, T. A. Rynearson, M. A. Saito, M. L. Mercier, H. Alexander, L. P. Whitney, A. Drzewianowski, V. V. Bulygin, E. M. Bertrand, Z. Wu, C. Benitez-Nelson, & A. Heithoff. (2012). The transcriptome and proteome of the diatom Thalassiosira pseudonana reveal a diverse phosphorus stress response. PLoS One, 7(3), e33768. doi: 10.1371/journal.pone.0033768

Mackey, K. R., A. Paytan, K. Caldeira, A. R. Grossman, D. Moran, M. McIlvin, & M. A. Saito. (2013). Effect of temperature on photosynthesis and growth in marine Synechococcus spp. Plant Physiol, 163(2), 815-829. doi: 10.1104/pp.113.221937

Moore, C. M., M. M. Mills, K. R. Arrigo, I. Berman-Frank, L. Bopp, P. W. Boyd, E. D.  Galbraith, R. J. Geider, C. Guieu, T. D. Jickells, J. La Roche, T. M. Lenton, N. M. Mahowald, E. Maranon, I. Marinov, J. K. Moore, T. Nakatsuka, A. Oschlies, M. A. Saito, T. F. Thingstad, A. Tsuda, & O. Ulloa. (2013). Processes and patterns of oceanic nutrient limitation. Nature Geosci, 6, 701-710.doi: 10.1038/ngeo1765

Noble, A.E., C.H. Lamborg, D.C. Ohnemus, P.J. Lam, T.J. Goepfert, C.I. Measures, C.H. Frame, K.L. Casciotti, G. R. DiTullio, J. Jennings, & M. A. Saito. (2012). Basin-scale inputs of cobalt, iron, and manganese from the Benguela-Angola front to the South Atlantic Ocean. Limnol Oceanogr, 57(4), 989-1010. doi: 10.4319/lo.2012.57.4.0989 

Noble, A.E., D.M. Moran, A.E. Allen, & M.A. Saito. (2013). Dissolved and particulate trace metal micronutrients under the McMurdo Sound seasonal sea ice: basal sea ice communities as a capacitor for iron. Front Chemdoi: 10.3389/fchem.2013.00025

Robbins, L. J., S. V. Lalonde, M. A. Saito, N. J. Planavsky, A. M. Mloszewska, E. Pecoits, C. Scott, C. L. Dupont, A. Kappler, & K. O. Konhauser. (2013). Authigenic iron oxide proxies for marine zinc over geological time and implications for eukaryotic metallome evolution. Geobiology, 11(4), 295-306. doi: 10.1111/gbi.12036

Saito, M. A. (2012). The rise of oxygen and aerobic biochemistry. Structure, 20(1), 1-2.

Saito, M. A., V. V. Bulygin, D. M. Moran, C. Taylor, & C. Scholin. (2011). Examination of microbial proteome preservation techniques applicable to autonomous environmental sample collection. Front Microbiol, 2, 215. doi: 10.3389/fmicb.2011.00215

Saito, M.A., A. E. Noble, A. Tagliabue, T.J. Geopfert, C. H. Lamborg, & W.J. Jenkins. (2013). Slow-spreading submarine ridges in the South Atlantic as a significant oceanic iron source. Nature Geosci, 3, 775-779. doi: 10.1038/ngeo1893



Living Lab Live radio interview, National Public Radio WCAI, June 3, 2013

Lyme disease metalloprotein (lack of iron requirement) press release

Oceanus article on Diazotroph Proteomic Research

Oceanus article on Vitamin B12 Claw and Proteomics

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