Extraction and liposome reconstitution of membrane proteins with their native lipids without the use of detergents.

Functional studies of membrane-bound channels, transporters or signal transducers require that the protein of interest resides in a membrane that separates two compartments. One approach that is commonly used to prepare these systems is to reconstitute the protein in liposomes. An intermediate step of this method is purification of the protein, which typically involves solubilization of the native membrane using detergent.

Isolation of yeast complex IV in native lipid nanodiscs.

We used the amphipathic styrene maleic acid (SMA) co-polymer to extract cytochrome c oxidase (CytcO) in its native lipid environment from S. cerevisiae mitochondria. Native nanodiscs containing one CytcO per disc were purified using affinity chromatography.

Electron and proton transfer in the ba(3) oxidase from Thermus thermophilus.

The ba(3)-type cytochrome c oxidase from Thermus thermophilus is phylogenetically very distant from the aa(3)-type cytochrome c oxidases. Nevertheless, both types of oxidases have the same number of redox-active metal sites and the reduction of O(2) to water is catalysed at a haem a(3)-Cu(B) catalytic site. The three-dimensional structure of the ba(3) oxidase reveals three possible proton-conducting pathways showing very low homology compared to those of the mitochondrial, Rhodobacter sphaeroides and Paracoccus denitrificans aa(3) oxidases.

Development of a bacterial biosensor for nitrotoluenes: the crystal structure of the transcriptional regulator DntR.

The transcriptional regulator DntR, a member of the LysR family, is a central element in a prototype bacterial cell-based biosensor for the detection of hazardous contamination of soil and groundwater by dinitrotoluenes. To optimise the sensitivity of the biosensor for such compounds we have chosen a rational design of the inducer-binding cavity based on knowledge of the three-dimensional structure of DntR. We report two crystal structures of DntR with acetate (resolution 2.