Ligand-free open-closed transitions of periplasmic binding proteins: the case of glutamine-binding protein.

ABSTRACT: The ability to undergo large-scale domain rearrangements is essential for the substrate-binding function of periplasmic binding proteins (PBPs), which are indispensable for nutrient uptake in Gram-negative bacteria. Crystal structures indicate that PBPs typically adopt either an "open" unliganded configuration or a "closed" liganded one. However, it is not clear whether, as a general rule, PBPs remain open until ligand-induced interdomain closure or are in equilibrium with a minor population of unliganded, closed species. Evidence for the latter has been recently reported on maltose-binding protein (MBP) in aqueous solution [Tang, C., et al. (2007) Nature 449, 1078-1082] via paramagnetic relaxation enhancement (PRE), a technique able to probe lowly populated regions of conformational space

SUBMITTER: Bermejo GA 

PROVIDER: S-EPMC2831130 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature