The bioindustrial production of fuels, chemicals, and therapeutics typically relies upon carbohydrate inputs derived from agricultural plants, resulting in the entanglement food chemical commodity markets. We demonstrate efficient sucrose a cyanobacterial species, Synechococcus elongatus, heterologously expressing symporter protons (cscB). cscB-expressing cyanobacteria export irreversibly to concentrations >10 mM without culture toxicity. Moreover, sucrose-exporting exhibit increased biomass...

Eukaryotic sugar transporters of the MFS and SWEET superfamilies consist 12 7 α-helical transmembrane domains (TMs), respectively. Structural analyses indicate that evolved from a series tandem duplications an ancestral 3-TM unit. SWEETs are heptahelical proteins carrying repeat separated by single TM. Here, we show prokaryotes have homologs with only Bradyrhizobium japonicum SemiSWEET1, like Arabidopsis SWEET11, mediates sucrose transport. most likely internal duplication 3-TM, suggesting...

Hydrogenases catalyze the reversible reaction 2H(+) + 2e(-) ↔ H(2) with an equilibrium constant that is dependent on reducing potential of electrons carried by their redox partner. To examine possibility increasing photobiological production hydrogen within cyanobacterial cultures, we expressed [FeFe] hydrogenase, HydA, from Clostridium acetobutylicum in non-nitrogen-fixing cyanobacterium Synechococcus elongatus sp. 7942. We demonstrate heterologously hydrogenase functional vitro and vivo,...

Microbial consortia composed of autotrophic and heterotrophic species abound in nature, yet examples synthetic communities with mixed metabolism are limited the laboratory. We previously engineered a model cyanobacterium, Synechococcus elongatus PCC 7942, to secrete bulk carbon it fixes as sucrose, carbohydrate that can be utilized by many other microbes. Here, we tested capability sucrose-secreting cyanobacteria act flexible platform for construction synthetic, light-driven pairing them...

Carboxysomes are protein-based bacterial organelles encapsulating key enzymes of the Calvin-Benson-Bassham cycle. Previous work has implicated a ParA-like protein (hereafter McdA) as important for spatially organizing carboxysomes along longitudinal axis model cyanobacterium Synechococcus elongatus PCC 7942. Yet, how self-organization McdA emerges and contributes to carboxysome positioning is unknown. Here, we identify small protein, termed McdB that localizes drives emergent oscillatory...

Significance Cyanobacteria have been increasingly explored as a biotechnological platform, although their economic feasibility relies in part on the capacity to maximize photosynthetic, solar-to-biomass energy conversion efficiency. Here we show that cyanobacterial photosynthetic can be increased by diverting cellular resources toward heterologous, energy-storing metabolic pathways and reducing electron flow photoprotective, but energy-dissipating, oxygen reduction reactions. We further...

The engineering of metabolism holds tremendous promise for the production desirable metabolites, particularly alternative fuels and other highly reduced molecules. Engineering approaches must redirect transfer chemical reducing equivalents, preventing these electrons from being lost to general cellular metabolism. This is especially case high energy stored in iron-sulfur clusters within proteins, which are readily transferred when two such brought close proximity. Iron sulfur proteins...

Bacterial microcompartments (BMCs) are self-assembling organelles composed of a selectively permeable protein shell and encapsulated enzymes. They considered promising templates for the engineering designed bionanoreactors biotechnology. In particular, encapsulation oxidoreductive reactions requiring electron transfer between lumen BMC cytosol relies on ability to conduct electrons across shell. We determined crystal structure component synthetic shell, which informed rational design...

As synthetic biology advances the intricacy of engineered biological systems, importance spatial organization within cellular environment must not be marginalized. Increasingly, engineers are investigating means to control cell, mimicking strategies used by natural pathways increase flux and reduce cross-talk. A modular platform for constructing a diverse set defined, programmable architectures would greatly assist in improving yields from introduced metabolic increasing insulation other...

In plants, a limited capacity to utilize or export the end-products of Calvin-Benson cycle (CB) from photosynthetically active source cells non-photosynthetic sink can result in reduced carbon capture and photosynthetic electron transport (PET), lowered photochemical efficiency. The down-regulation photosynthesis caused by photosynthate has been termed 'sink limitation'. Recently, several cyanobacterial algal strains engineered overproduce target metabolites have exhibited increased...

Photosynthetic organisms possess a variety of mechanisms to achieve balance between absorbed light (source) and the capacity metabolically utilize or dissipate this energy (sink). While regulatory processes that detect changes in metabolic status/balance are relatively well studied plants, analogous pathways remain poorly characterized photosynthetic microbes. Here, we explored systemic result from alterations carbon availability model cyanobacterium Synechococcus elongatus PCC 7942 by...

Carboxysomes are bacterial microcompartments that encapsulate Rubisco and a core component of the cyanobacterial carbon concentration mechanism (CCM). While carboxysome number, size spatial organization observed to vary in different environmental conditions (CO2, light, temperature, light quality), molecular mechanisms underlying this potentially adaptive process remain elusive. Herein, we mutants circadian rhythm/metabolism factor, Regulator Phycobilisome Associated A (RpaA), exhibit...

Despite significant potential for cyanobacteria as sustainable bioproduction chases, there are limited examples of scaled cyanobacterial bioproduction. In part, this is because most species poorly adapted to bioreactor cultivation conditions and lack features that facilitate biomass growth harvesting at scale. We explored quorum sensing (QS) pathways derived from heterotrophic microbes a method autoinduction gene expression circuits coordinated population density in cyanobacteria. Here, we...

To identify novel proteins important for microtubule assembly in mitosis, we have used a centrosome-based complementation assay to enrich with mitotic functions. An RNA interference (RNAi)-based screen of these allowed us uncover 13 regulators. We carried out in-depth analyses one proteins, Pontin, which is known several functions interphase, including chromatin remodeling, DNA repair, and transcription. show that reduction Pontin by RNAi resulted defects spindle Drosophila S2 cells...

In contrast to the current paradigm of using microbial mono-cultures in most biotechnological applications, increasing efforts are being directed towards engineering mixed-species consortia perform functions that difficult programme into individual strains. this work, we developed a synthetic consortium composed two genetically engineered microbes, cyanobacterium (Synechococcus elongatus PCC 7942) and heterotrophic bacterium (Pseudomonas putida EM173). These species specialize co-culture:...

Summary The oscillatory Min system of Escherichia coli defines the cell division plane by regulating site FtsZ‐ring formation and represents one best‐understood examples emergent protein self‐organization in nature. patterns Min‐system proteins MinC, MinD MinE (MinCDE) are strongly dependent on geometry membranes they bind. Complex internal within cyanobacteria could disrupt this sterically occluding or sequestering MinCDE from plasma membrane. Here, it was shown that cyanobacterium...