Exploring the function and structure of the acetate transporter family

Abstract

The AceTr transporter family is a group of Acetate Transporters with six predicted transmembrane segments. It has homologues in fungi, bacteria, archaea and protozoa. As acetate transporters, these proteins play a crucial role on cell metabolism being involved in the capacity of cells to adapt to nutrient availability. As these membrane transporters also transport other substrates, they may be an important asset for biotechnological purposes. To better understand the mechanism of acetate transport, we have investigated functional and structural features of the AceTr family. We have performed site-directed mutagenesis in residues highly conserved, or possibly involved in substrate binding, from the Saccharomyces cerevisiae Ady2. Functional assays determined the influence of these residues on the transport capacity and protein localization. Another goal of this work is to determine the structure of the AceTr family. Accordingly, several of its members were cloned in different expression vectors and their expression was evaluated in different E. coli expression strains. SatP from E. coli and its AceP from Methanosarcina acetivorans presented satisfactory levels of protein production and are currently being tested in production, purification and crystallization trials.