Felisa Wolfe-Simon's poster at the Dec. 2011 AGU meeting

I just found the Abstract for a poster presented by Felisa Wolfe-Simon at this month's American Geophysical Union Annual Meeting.

TITLE: Characterizations of intracellular arsenic in a bacterium

SESSION TYPE: Poster

SESSION TITLE: B51G. Life Under Stress: How Do Microbes Cope?

AUTHORS: Felisa Wolfe-Simon, Steven M. Yannone, John A. Tainer^.  Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States.

ABSTRACT: Life requires a key set of chemical elements to sustain growth. Yet, a growing body of literature suggests that microbes can alter their nutritional requirements based on the availability of these chemical elements. Under limiting conditions for one element microbes have been shown to utilize a variety of other elements to serve similar functions often (but not always) in similar molecular structures. Well-characterized elemental exchanges include manganese for iron, tungsten for molybdenum and sulfur for phosphorus or oxygen. These exchanges can be found in a wide variety of biomolecules ranging from protein to lipids and DNA. Recent evidence suggested that arsenic, as arsenate or As(V), was taken up and incorporated into the cellular material of the bacterium GFAJ-1. The evidence was interpreted to support As(V) acting in an analogous role to phosphate. We will therefore discuss our ongoing efforts to characterize intracellular arsenate and how it may partition among the cellular fractions of the microbial isolate GFAJ-1 when exposed to As(V) in the presence of various levels of phosphate. Under high As(V) conditions, cells express a dramatically different proteome than when grown given only phosphate. Ongoing studies on the diversity and potential role of proteins and metabolites produced in the presence of As(V) will be reported. These investigations promise to inform the role and additional metabolic potential for As in biology. Arsenic assimilation into biomolecules contributes to the expanding set of chemical elements utilized by microbes in unusual environmental niches.