GENE-FUSION TECHNIQUES FOR DETERMINING MEMBRANE-PROTEIN TOPOLOGY

Gene-fusion systems for mapping membrane-protein topology depend on fusing a reporter molecule which exhibits location-specific phenotypes to progressively truncated versions of the membrane protein. The most elegant systems available are those developed for use in Escherichia coli where the reporters advertise whether they have been retained in the cytoplasm by expression of simple phenotypes. The judicious application of such systems can reveal the organization of many proteins in the bacterial cytoplasmic membrane, as well as providing insights into the processes governing membrane assembly.