CYP77B1 a fatty acid epoxygenase specific to flowering plants.

Contrary to animals, little is known in plants about enzymes able to produce fatty acid epoxides. In our attempt to find and characterize a new fatty acid epoxygenase in Arabidopsis thaliana, data mining brought our attention on CYP77B1. Modification of the N-terminus was necessary to get enzymatic activity after heterologous expression in yeast.

Extrinsic noise prevents the independent tuning of gene expression noise and protein mean abundance in bacteria.

It is generally accepted that prokaryotes can tune gene expression noise independently of protein mean abundance by varying the relative levels of transcription and translation. Here, we address this question quantitatively, using a custom-made library of 40 strains expressing a fluorescent protein under the control of different transcription and translation control elements. We quantify noise and mean protein abundance by fluorescence microscopy and show that for most of the natural transcription range of , expression noise is equally sensitive to variations in the transcription or translation rate because of the prevalence of extrinsic noise.

Bacterial growth physiology and RNA metabolism.

Bacteria are sophisticated systems with high capacity and flexibility to adapt to various environmental conditions. Each prokaryote however possesses a defined metabolic network, which sets its overall metabolic capacity, and therefore the maximal growth rate that can be reached. To achieve optimal growth, bacteria adopt various molecular strategies to optimally adjust gene expression and optimize resource allocation according to the nutrient availability.

In vivo evolution of metabolic pathways: Assembling old parts to build novel and functional structures.

In our recent article "In vivo evolution of metabolic pathways by homeologous recombination in mitotic cells" we proposed a useful alternative to directed evolution methods that permits the generation of yeast cell libraries containing recombinant metabolic pathways from counterpart genes. The methodology was applied to generate single mosaic genes and intragenic mosaic pathways. We used flavonoid metabolism genes as a working model to assembly and express evolved pathways in DNA repair deficient cells.