Project description:Bacterial α-type carbonic anhydrase (α-CA) is a zinc metalloenzyme that catalyzes the reversible and extremely rapid interconversion of carbon dioxide to bicarbonate. In this study, we report the first crystal structure of a hyperthermostable α-CA from Persephonella marina EXH1 (pm CA) in the absence and presence of competitive inhibitor, acetazolamide. The structure reveals a compactly folded pm CA homodimer in which each monomer consists of a 10-stranded β-sheet in the center. The catalytic zinc ion is coordinated by three highly conserved histidine residues with an exchangeable fourth ligand (a water molecule, a bicarbonate anion, or the sulfonamide group of acetazolamide). Together with an intramolecular disulfide bond, extensive interfacial networks of hydrogen bonds, ionic and hydrophobic interactions stabilize the dimeric structure and are likely responsible for the high thermal stability. We also identified novel binding sites for calcium ions at the crystallographic interface, which serve as molecular glue linking negatively charged and otherwise repulsive surfaces. Furthermore, this large negatively charged patch appears to further increase the thermostability at alkaline pH range via favorable charge-charge interactions between pm CA and solvent molecules. These findings may assist development of novel α-CAs with improved thermal and/or alkaline stability for applications such as CO2 capture and sequestration.
Project description:The Lucinidae is a large family of marine bivalves. They occur in diverse habitats from shallow-water seagrass sediments to deep-sea hydrothermal vents. All members of this family so far investigated host intracellular sulfur-oxidizing symbionts that belong to the Gammaproteobacteria. We recently discovered the capability for nitrogen fixation in draft genomes of the symbionts of Loripes lucinalis from the Bay of Fetovaia, Elba, Italy. With proteomics, we investigated whether the genes for nitrogen fixation are expressed by the symbionts.
Project description:Bathymodiolin mussels are a group of bivalves associated with deep-sea reducing habitats, such as hydrothermal vents and cold seeps. These mussels usually engage in an obligatory symbiosis with sulfur and/or methane oxidizing Gammaproteobacteria. In addition to these bacteria, Bathymodiolus heckerae that inhabit gas and oil seeps in Campeche Bay, the southern Gulf of Mexico, host bacteria phylogenetically with the Cycloclasticus genus. We recently discovered the capability for short-chain alkane degradation in draft genomes of symbiotic Cycloclasticus. With proteomics, we investigated whether the genes required for this process are expressed by the symbionts.
Project description:<p>Deep-sea hydrothermal vents are unique ecosystems that may release chemically distinct dissolved organic matter to the deep ocean. Here, we describe the composition and concentrations of polar dissolved organic compounds observed in low and high temperature hydrothermal vent fluids at 9°50′N on the East Pacific Rise. The concentration of dissolved organic carbon was 46 µM in the low temperature hydrothermal fluids and 14 µM in the high temperature hydrothermal fluids. In the low temperature vent fluids, quantifiable dissolved organic compounds were dominated by water-soluble vitamins and amino acids. Derivatives of benzoic acid and the organic sulfur compound 2,3-dihydroxypropane-1-sulfonate (DHPS) were also present in low and high temperature hydrothermal fluids. The low temperature vent fluids contain organic compounds that are central to biological processes, suggesting that they are a by-product of biological activity in the subseafloor. These compounds may fuel heterotrophic and other metabolic processes at deep-sea hydrothermal vents and beyond.</p>
Project description:Colonization of deep-sea hydrothermal vents by invertebrates was made efficient through their adaptation to a symbiotic lifestyle with chemosynthetic bacteria, the primary producers of these ecosystems. Anatomical adaptations such as the establishment of specialized cells or organs have been evidenced in numerous deep-sea invertebrates. However, very few studies detailed global inter-dependencies between host and symbionts in these ecosystems. In this study, we proposed to describe, using a proteo-transcriptomic approach, the effects of symbionts on the deep-sea mussel Bathymodiolus azoricus’ molecular biology. We induced an in situ depletion of symbionts and compared the proteo-transcriptome of the gills of mussels in three conditions: symbiotic mussels (natural population), symbiont-depleted mussels and aposymbiotic mussels
Project description:This data set was downloaded from MetaboLights (http://www.ebi.ac.uk/metabolights/) accession number MTBLS428 Abstract:"Deep-sea hydrothermal vents are unique ecosystems that may provide chemically distinct dissolved organic matter to the deep ocean. Here, we describe the types and concentrations of polar dissolved organic compounds observed at low and high temperature hydrothermal vents at 9°50’N, the East Pacific Rise. The concentration of dissolved organic carbon was 46 µM in the low temperature hydrothermal fluids and 14 µM in the high temperature hydrothermal fluids. In the low temperature vent fluids, identifiable dissolved organic compounds were dominated by water-soluble vitamins and amino acids. Derivatives of benzoic acid and the organic sulfur compound 2,3-dihydroxypropane-1-sulfonate (DHPS) were also present in low and high temperature hydrothermal fluids. Thus, low temperature vent fluids contain organic compounds that are central to biological processes, suggesting that they are a by-product of subseafloor biological activity. These compounds may fuel heterotrophic, metabolic processes at deep-sea hydrothermal vents and beyond."
Project description:We designed an experimental setup to investigate the transcriptomic and proteomic responses of the hyperthermophilic archaeon Pyrococcus furiosus to heat and cold shock. P. furiosus is a model organism for studying microbial adaptation to extreme environments, including deep-sea hydrothermal vents with temperature gradients ranging from 1°C to 400°C. We aimed to simulate critical conditions where P. furiosus cannot grow and to examine the immediate response to thermal stress as well as the recovery process.