A high security double lock and key mechanism in HUH relaxases controls oriT-processing for plasmid conjugation.

Relaxases act as DNA selection sieves in conjugative plasmid transfer. Most plasmid relaxases belong to the HUH endonuclease family. TrwC, the relaxase of plasmid R388, is the prototype of the HUH relaxase family, which also includes TraI of plasmid F.

Diplogelasinospora grovesii IMI 171018 immobilized in polyurethane foam. An efficient biocatalyst for stereoselective reduction of ketones.

Diplogelasinospora grovesii has been reported as a very active biocatalyst in the reduction of ketones. Along the text, the properties of this filamentous fungus as an immobilized catalyst are described. For this purpose, several immobilization supports as agar and polyurethane foam were tested.

Increasing the stability of an enzyme toward hostile organic solvents by directed evolution based on iterative saturation mutagenesis using the B-FIT method.

Mutants of the lipase from Bacillus subtilis, previously engineered for enhanced thermostability using directed evolution based on the B-FIT method, show significantly increased tolerance to hostile organic solvents.

Iterative saturation mutagenesis accelerates laboratory evolution of enzyme stereoselectivity: rigorous comparison with traditional methods.

Efficacy in laboratory evolution of enzymes is currently a pressing issue, making comparative studies of different methods and strategies mandatory. Recent reports indicate that iterative saturation mutagenesis (ISM) provides a means to accelerate directed evolution of stereoselectivity and thermostability, but statistically meaningful comparisons with other methods have not been documented to date. In the present study, the efficacy of ISM has been rigorously tested by applying it to the previously most systematically studied enzyme in directed evolution, the lipase from Pseudomonas aeruginosa as a catalyst in the stereoselective hydrolytic kinetic resolution of a chiral ester.

Microbial cells as catalysts for stereoselective red-ox reactions.

Enzyme catalyzed reactions are commonly used at laboratory or industrial scale. Contrarily, the whole cell catalyzed reactions are restricted to special cases. The tremendous advances in the last years in Molecular Biology and more specifically in Metabolic Engineering and Directed Enzyme Evolution have opened the door to create tailor-made microorganisms or "designer bugs" for industrial purposes.