United States Department of Energy

About: United States Department of Energy is a government organization based out in Washington D.C., District of Columbia, United States. It is known for research contribution in the topics: Catalysis & Coal. The organization has 13656 authors who have published 14177 publications receiving 556962 citations. The organization is also known as: DOE & Department of Energy.

Latent homology and convergent regulatory evolution underlies the repeated emergence of yeasts

Abstract: Convergent evolution is common throughout the tree of life, but the molecular mechanisms causing similar phenotypes to appear repeatedly are obscure. Yeasts have arisen in multiple fungal clades, but the genetic causes and consequences of their evolutionary origins are unknown. Here we show that the potential to develop yeast forms arose early in fungal evolution and became dominant independently in multiple clades, most likely via parallel diversification of Zn-cluster transcription factors, a fungal-specific family involved in regulating yeast-filamentous switches. Our results imply that convergent evolution can happen by the repeated deployment of a conserved genetic toolkit for the same function in distinct clades via regulatory evolution. We suggest that this mechanism might be a common source of evolutionary convergence even at large time scales.

Mimicry of the Radical Pair and Triplet States in Photosynthetic Reaction Centers with a Synthetic Model

Abstract: Supramolecular systems synthesized to model the photosynthetic reaction center (RC) are designed to mimic several key properties of the RC protein. Thus far, most RC models fulfill only a subset of these criteria, with very few reports employing time-resolved electron paramagnetic resonance spectroscopy (TREPR). We now report TREPR results on a photosynthetic model system (1) in a nematic liquid crystal (LC) that does not contain the natural pigments, yet closely mimics the spin dynamics of triplet state formation found only in photosynthetic RCs. The design of supermolecule 1 follows criteria established for promoting high quantum yield charge separation in glassy media. The observation of this triplet state in 1 by TREPR demonstrates that most of the electronic states found in the primary photochemistry of photosynthetic RCs can be mimicked successfully in synthetic models interacting with LCs. 12 refs., 3 figs.