VerBerkmoes Nathan C.

No Thumbnail Available
Last Name
VerBerkmoes
First Name
Nathan C.
ORCID

Filters

2008 - 2009 1 2010 - 2011 1
1 1
2
Reset filters

Settings

Search Results

Now showing 1 - 2 of 2
  • Article
    Characterization of cytochrome 579, an unusual cytochrome isolated from an iron-oxidizing microbial community
    (American Society for Microbiology, 2008-05-09) Singer, Steven W. ; Chan, Clara S. ; Zemla, Adam ; VerBerkmoes, Nathan C. ; Hwang, Mona ; Hettich, Robert L. ; Banfield, Jillian F. ; Thelen, Michael P.
    A novel, soluble cytochrome with an unusual visible spectral signature at 579 nm (Cyt579) has been characterized after isolation from several different microbial biofilms collected in an extremely acidic ecosystem. Previous proteogenomic studies of an Fe(II)-oxidizing community indicated that this abundant red cytochrome could be extracted from the biofilms with dilute sulfuric acid. Here, we found that the Fe(II)-dependent reduction of Cyt579 was thermodynamically favorable at a pH of >3, raising the possibility that Cyt579 acts as an accessory protein for electron transfer. The results of transmission electron microscopy of immunogold-labeled biofilm indicated that Cyt579 is localized near the bacterial cell surface, consistent with periplasmic localization. The results of further protein analysis of Cyt579, using preparative chromatofocusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, revealed three forms of the protein that correspond to different N-terminal truncations of the amino acid sequence. The results of intact-protein analysis corroborated the posttranslational modifications of these forms and identified a genomically uncharacterized Cyt579 variant. Homology modeling was used to predict the overall cytochrome structure and heme binding site; the positions of nine amino acid substitutions found in three Cyt579 variants all map to the surface of the protein and away from the heme group. Based on this detailed characterization of Cyt579, we propose that Cyt579 acts as an electron transfer protein, shuttling electrons derived from Fe(II) oxidation to support critical metabolic functions in the acidophilic microbial community.
  • Preprint
    Niche of harmful alga Aureococcus anophagefferens revealed through ecogenomics
    ( 2011-01) Gobler, Christopher J. ; Berry, Dianna L. ; Dyhrman, Sonya T. ; Wilhelm, Steven W. ; Salamov, Asaf ; Lobanov, Alexei V. ; Zhang, Yan ; Collier, Jackie L. ; Wurch, Louie L. ; Kustka, Adam B. ; Dill, Brian D. ; Shah, Manesh ; VerBerkmoes, Nathan C. ; Kuo, Alan J. ; Terry, Astrid ; Pangilinan, Jasmyn ; Lindquist, Erika A. ; Lucas, Susan ; Paulsen, Ian T. ; Hattenrath-Lehmann, Theresa K. ; Talmage, Stephanie C. ; Walker, Elyse A. ; Koch, Florian ; Burson, Amanda M. ; Marcoval, Maria Alejandra ; Tang, Ying-Zhong ; LeCleir, Gary R. ; Coyne, Kathryn J. ; Berg, Gry M. ; Bertrand, Erin M. ; Saito, Mak A. ; Gladyshev, Vadim N. ; Grigoriev, Igor V.
    Harmful algal blooms (HABs) cause significant economic and ecological damage worldwide. Despite considerable efforts, a comprehensive understanding of the factors that promote these blooms has been lacking because the biochemical pathways that facilitate their dominance relative to other phytoplankton within specific environments have not been identified. Here, biogeochemical measurements demonstrated that the harmful 43 Aureococcus anophagefferens outcompeted co-occurring phytoplankton in estuaries with elevated levels of dissolved organic matter and turbidity and low levels of dissolved inorganic nitrogen. We subsequently sequenced the first HAB genome (A. anophagefferens) and compared its gene complement to those of six competing phytoplankton species identified via metaproteomics. Using an ecogenomic approach, we specifically focused on the gene sets that may facilitate dominance within the environmental conditions present during blooms. A. anophagefferens possesses a larger genome (56 mbp) and more genes involved in light harvesting, organic carbon and nitrogen utilization, and encoding selenium- and metal-requiring enzymes than competing phytoplankton. Genes for the synthesis of microbial deterrents likely permit the proliferation of this species with reduced mortality losses during blooms. Collectively, these findings suggest that anthropogenic activities resulting in elevated levels of turbidity, organic matter, and metals have opened a niche within coastal ecosystems that ideally suits the unique genetic capacity of A. anophagefferens and thus has facilitated the proliferation of this and potentially other HABs.