2009 Annual Science Report
Arizona State University Reporting | JUL 2008 – AUG 2009
Stoichiometry of Life, Task 3b: Ancient Records - Genomic
The genomic records of modern organisms carry clues to the evolution of the use of elements in biology. We are investigating these records in several ways, with a particular emphasis on the use of metals in enzyme active sites and nitrogen fixation.
We are focusing on resolving the role of element cycling and limitations as inferred from ancient genomic records. Team members have been involved in a number of synergistic projects that play both direct and supporting roles in accomplishing this overarching goal. This includes a new investigation of the evolutionary history of nitrogen fixation, in particular focusing on a new clade of unique thermophilic and hyperthermophilic nitrogenases with unexpected metal specificity (co-I Raymond). This work was presented at an invited talk at the 16th International Conference on Nitrogen Fixation in June 2009, with a manuscript in preparation. Team members have been interacting with other NAI teams (Montana State University) to develop new methods of calibration for investigating the early molecular record of nitrogen cycling (particularly collaborations between PI Anbar, co-I Siefert, MSU PI John Peters and MSU postdoc Eric Boyd). In addition, Department of Energy/Joint Genome Institute funding-for-sequencing has recently been obtained to sequence the metabolome and transcriptome of microbialites from Cuatro Cienegas (co-I Siefert), which will provide an enormous repository of new genomic data coupled to biogeochemical measurements of nutrient cycling. Finally, strong support from the ASU NAI initiative has helped secure NASA Director’s Discretionary Funding for a team member’s work investigating the relative ages of all known metal-binding protein families, identifying two scenarios where trace metals presented a significant barrier to the evolution of life (collaborator DuPont). A manuscript detailing these findings has recently been submitted to PNAS.
PROJECT INVESTIGATORS:Jason Raymond
PROJECT MEMBERS:Ariel Anbar
RELATED OBJECTIVES:Objective 5.1
Environment-dependent, molecular evolution in microorganisms
Co-evolution of microbial communities
Biochemical adaptation to extreme environments