Site-directed mutagenesis in the study of membrane transporters

One of the major goals in membrane transporter research is to understand how transporter proteins work at the molecular level. Ideally, this research would be carried out with a detailed knowledge of the three-dimensional structure of the protein. However, in the absence of atomic resolution structures for many membrane transporters other molecular tools need to be employed. In vitro site-directed mutagenesis is one method that has the capacity to provide both structural information and identification of the role of individual residues and/or regions of a protein that are involved in function.