English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The periplasmic binding protein (PBP) IbpA mediates the uptake ofmyo -inositol by the IatP-IatA ATP-binding cassette transmembrane transporter. We report a crystal structure ofCaulobacter crescentus IbpA bound tomyo -inositol at 1.45 Å resolution. This constitutes the first structure of a PBP bound to inositol. IbpA adopts a type I PBP fold consisting of two α-β lobes that surround a central hinge. A pocket positioned between the lobes contains themyo -inositol ligand, which binds with submicromolar affinity (0.76 ± 0.08 μM). IbpA is homologous to ribose-binding proteins and bindsd -ribose with low affinity (50.8 ± 3.4 μM). On the basis of IbpA and ribose-binding protein structures, we have designed variants of IbpA with inverted binding specificity formyo -inositol andd -ribose. Five mutations in the ligand-binding pocket are sufficient to increase the affinity of IbpA ford -ribose by 10-fold while completely abolishing binding tomyo -inositol. Replacement ofibpA with these mutant alleles unable to bindmyo -inositol abolishesC. crescentus growth in medium containingmyo -inositol as the sole carbon source. Neither deletion ofibpA nor replacement ofibpA with the high-affinity ribose binding allele affectedC. crescentus growth ond -ribose as a carbon source, providing evidence that the IatP-IatA transporter is specific formyo -inositol. This study outlines the evolutionary relationship between ribose- and inositol-binding proteins and provides insight into the molecular basis upon which these two related, but functionally distinct, classes of periplasmic proteins specifically bind carbohydrate ligands.

myo -Inositol and d -Ribose Ligand Discrimination in an ABC Periplasmic Binding Protein