Crystal structures of an Extracytoplasmic Solute Receptor from a TRAP transporter in its open and closed forms reveal a helix-swapped dimer requiring a cation for alpha-keto acid binding.

ABSTRACT:

Background

The import of solutes into the bacterial cytoplasm involves several types of membrane transporters, which may be driven by ATP hydrolysis (ABC transporters) or by an ion or H+ electrochemical membrane potential, as in the tripartite ATP-independent periplasmic system (TRAP). In both the ABC and TRAP systems, a specific periplasmic protein from the ESR family (Extracytoplasmic Solute Receptors) is often involved for the recruitment of the solute and its presentation to the membrane complex. In Rhodobacter sphaeroides, TakP (previously named SmoM) is an ESR from a TRAP transporter and binds alpha-keto acids in vitro.

Results

We describe the high-resolution crystal structures of TakP in its unliganded form and as a complex with sodium-pyruvate. The results show a lim

SUBMITTER: Gonin S 

PROVIDER: S-EPMC1839085 | biostudies-literature | 2007 Mar

REPOSITORIES: biostudies-literature