Conformational coupling of the sialic acid TRAP transporter HiSiaQM with its substrate binding protein HiSiaP.

ABSTRACT: The tripartite ATP-independent periplasmic (TRAP) transporters use an extra cytoplasmic substrate binding protein (SBP) to transport a wide variety of substrates in bacteria and archaea. The SBP can adopt an open- or closed state depending on the presence of substrate. The two transmembrane domains of TRAP transporters form a monomeric elevator whose function is strictly dependent on the presence of a sodium ion gradient. Insights from experimental structures, structural predictions and molecular modeling have suggested a conformational coupling between the membrane elevator and the substrate binding protein. Here, we use a disulfide engineering approach to lock the TRAP transporter HiSiaPQM from Haemophilus influenzae in different conformational states. The SBP, HiSiaP, is locked in its s

SUBMITTER: Peter MF 

PROVIDER: S-EPMC10774421 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature