Extreme environments comprise intriguing niches where some particular microbes are thriving. They represent interesting case study in order to understand the origin of Life and the required conditions for possible extra-terrestrial Life. Arsenate-rich environments are challenging because of the high similarity between the toxic arsenate and the essential phosphate anions. Our group investigates the molecular basis of microbial survival in extreme environments, i.e. arsenate-rich, phosphate-depleted environments. Through the study of the cellular phosphate uptake system (Pst transporter), we identified unique, highly energetic chemical bonds that shields microbes from the toxic arsenate, and enable them to intake the necessary phosphate. The understanding of the mechanism and the formation of these bonds comprise key challenge in protein chemistry, and may provide critical insights for future development in protein design and engineering.