Cyanobacteria from marine oxygen-deficient zones encode both form I and form II Rubiscos.

Cyanobacteria are highly abundant in the marine photic zone and primary drivers of the conversion of inorganic carbon into biomass. To date, all studied cyanobacterial lineages encode carbon fixation machinery relying upon form I Rubiscos within a CO-concentrating carboxysome. Here, we report that the uncultivated anoxic marine zone (AMZ) IB lineage of from pelagic oxygen-deficient zones (ODZs) harbors both form I and form II Rubiscos, the latter of which are typically noncarboxysomal and possess biochemical properties tuned toward low-oxygen environments.

A map of the rubisco biochemical landscape.

Rubisco is the primary CO fixing enzyme of the biosphere yet has slow kinetics. The roles of evolution and chemical mechanism in constraining the sequence landscape of rubisco remain debated. In order to map sequence to function, we developed a massively parallel assay for rubisco using an engineered where enzyme function is coupled to growth.

Plant Cysteine Oxidase Oxygen-Sensing Function Is Conserved in Early Land Plants and Algae.

All aerobic organisms require O for survival. When their O is limited (hypoxia), a response is required to reduce demand and/or improve supply. A hypoxic response mechanism has been identified in flowering plants: the stability of certain proteins with N-terminal cysteine residues is regulated in an O-dependent manner by the Cys/Arg branch of the N-degron pathway.

Targeting plant cysteine oxidase activity for improved submergence tolerance.

Plant cysteine oxidases (PCOs) are plant O -sensing enzymes. They catalyse the O -dependent step which initiates the proteasomal degradation of Group VII ethylene response transcription factors (ERF-VIIs) via the N-degron pathway. When submerged, plants experience a reduction in O availability; PCO activity therefore decreases and the consequent ERF-VII stabilisation leads to upregulation of hypoxia-responsive genes which enable adaptation to low O conditions.

The plant cysteine oxidases from are kinetically tailored to act as oxygen sensors.

Group VII thylene esponse actors (ERF-VIIs) regulate transcriptional adaptation to flooding-induced hypoxia in plants. ERF-VII stability is controlled in an O-dependent manner by the Cys/Arg branch of the N-end rule pathway whereby oxidation of a conserved N-terminal cysteine residue initiates target degradation. This oxidation is catalyzed by lant ysteine xidases (PCOs), which use O as cosubstrate to generate Cys-sulfinic acid.

Preparation and characterisation of high-density ionic liquids incorporating halobismuthate anions.

A range of ionic liquids containing dialkylimidazolium cations and halobismuthate anions ([BiBr(x)Cl(y)I(z)](-) and [Bi2Br(x)Cl(y)I(z)](-)) were synthesised by combining dialkylimidazolium halide ionic liquids with bismuth(III) halide salts. The majority were room temperature liquids, all with very high densities. The neat ionic liquids and their mixtures with 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide were characterised using Densitometry, Viscometry, NMR Spectroscopy, Electrospray Ionisation Mass Spectrometry (ESI), Liquid Secondary Ion Mass Spectrometry (LSIMS), Matrix-assisted Laser Desorption/Ionization Mass Spectrometry (MALDI), X-Ray Photoelectron Spectroscopy (XPS) and Thermogravimetric Analysis (TGA), to establish their speciation and suitability for high-temperature applications.