Tag 1 | Beckstein Lab

Physics freshwoman undergraduate student Kacey Clark was selected as a Bidstrup Undergraduate Fellow for the 2016-2017 academic year. The Bidstrup Fellowship is awarded by Barrett, The Honors College at Arizona State University where Kacey is a student.

We studied the process of sodium/proton antiport in the NapA transporter. Through a combination of X-ray crystallography, biochemistry and computer simulations we could show that the antiporter undergoes a large conformational transition that resembles a *elevator*-like movement whereby a single domain moves up- and down through the membrane and carries a sodium ion with it.

A new crystal structure of the Escherichia coli NhaA dimer reveals a previously unidentified salt bridge between two highly conserved residues at the putative binding site. The combination of structural data with molecular dynamics simulations yields new insights into the transport mechanism.

The hydantoin transporter Mhp1 is a sodium?coupled secondary active transport protein of the nucleobase?cation?symport family and shares the widespread 5?helix inverted repeat transporter architecture. Our previous work showed Mhp1 functions according to the alternating access mechanism. In our new paper in EMBO J , we elucidate detailed events of substrate binding, through a combination of crystallography, molecular dynamics, site?directed mutagenesis, biochemical/biophysical assays, and the design and synthesis of novel ligands.

Structures of membrane proteins can be obtained by the experimental technique of X-ray crystallography. However, proteins are typically not crystallized in their native environment, the lipid membrane. Molecular dynamics simulations of the protein in the membrane provide a realistic model of the interactions between transporter and lipid bilayer.