Structural basis of catalysis in the bacterial monoterpene synthases linalool synthase and 1,8-cineole synthase

Terpenoids form the largest and stereochemically most diverse class of natural products, and there is considerable interest in producing these by biocatalysis with whole cells or purified enzymes, and by metabolic engineering. The monoterpenes are an important class of terpenes and are industrially important as flavors and fragrances. We report here structures for the recently discovered Streptomyces clavuligerus monoterpene synthases linalool synthase (bLinS) and 1,8-cineole synthase (bCinS), and we show that these are active biocatalysts for monoterpene production using biocatalysis and metabolic engineering platforms. In metabolically engineered monoterpene-producing E. coli strains, use of bLinS leads to 300-fold higher linalool production compared with the corresponding plant monoterpene synthase. With bCinS, 1,8-cineole is produced with 96% purity compared to 67% from plant species. Structures of bLinS and bCinS, and their complexes with fluorinated substrate analogues, show that these bacterial monoterpene synthases are similar to previously characterized sesquiterpene synthases. Molecular dynamics simulations suggest that these monoterpene synthases do not undergo large-scale conformational changes during the reaction cycle, making them attractive targets for structured-based protein engineering to expand the catalytic scope of these enzymes toward alternative monoterpene scaffolds. Comparison of the bLinS and bCinS structures indicates how their active sites steer reactive carbocation intermediates to the desired acyclic linalool (bLinS) or bicyclic 1,8-cineole (bCinS) products. The work reported here provides the analysis of structures for this important class of monoterpene synthase. This should now guide exploitation of the bacterial enzymes as gateway biocatalysts for the production of other monoterpenes and monoterpenoids

Quantum biology: an update and perspective

This is the final version. Available from MDPI via the DOI in this record. Data Availability Statement: Not applicable.Understanding the rules of life is one of the most important scientific endeavours and has revolutionised both biology and biotechnology. Remarkable advances in observation tech-niques allow us to investigate a broad range of complex and dynamic biological processes in which living systems could exploit quantum behaviour to enhance and regulate biological functions. Recent evidence suggests that these non-trivial quantum mechanical effects may play a crucial role in maintaining the non-equilibrium state of biomolecular systems. Quantum biology is the study of such quantum aspects of living systems. In this review, we summarise the latest progress in quantum biology, including the areas of enzyme-catalysed reactions, photosynthesis, spin-dependent reactions, DNA, fluorescent proteins, and ion channels. Many of these results are expected to be fundamental building blocks towards understanding the rules of life.Leverhulme Trus

Low carbon strategies for sustainable bio-alkane gas production and renewable energy

Propane and butane are the main constituents of liquefied petroleum gas and are used extensively for transport and domestic use. They are clean burning fuels, suitable for the development of low carbon footprint fuel and energy policies. Here, we present blueprints for the production of bio-alkane gas (propane and butane) through the conversion of waste volatile fatty acids by bacterial culture. We show that bio-propane and bio-butane can be produced photo-catalytically by bioengineered strains of E. coli and Halomonas (in non-sterile seawater) using fatty acids derived from biomass or industrial waste, and by Synechocystis (using carbon dioxide as feedstock). Scaled production using available infrastructure is calculated to be economically feasible using Halomonas. These fuel generation routes could be deployed rapidly, in both advanced and developing countries, and contribute to energy security to meet global carbon management targets and clean air directives