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

Lipoprotein FtsB is a component of the FtsABCD transporter that is responsible for ferrichrome binding and uptake in the Gram-positive pathogen  Streptococcus pyogenes . In the present study, FtsB was cloned and purified from the bacteria and its Fch binding characteristics were investigated in detail by using various biophysical and biochemical methods. Based on the crystal structures of homogeneous proteins, FtsB was simulated to have bi-lobal structure forming a deep cleft with four residues in the cleft as potential ligands for Fch binding. With the assistance of site-directed mutagenesis, residue Trp204 was confirmed as a key ligand and Tyr137 was identified to be another essential residue for Fch binding. Kinetics experiments demonstrated that Fch binding in FtsB occurred in two steps, corresponding to the bindings to Tyr137 at N-lobe and Trp204 from C-lobe, respectively, and so that closing the protein conformation. Without either residue Tyr137 or Trp204, Fch binding in the protein as mutants Fch-Y137A and Fch-W204A may have a loose conformation, resembling the apo-proteins in proteolysis resistance and migration behaviors in native gel. This study revealed the inconsistence in the key amino acids among Fch-binding proteins from Gram-positive and –negative bacteria, providing interesting findings for understanding the differences between Gram-positive and –negative bacteria in the mechanism of iron uptake via siderophore (Fch) binding and transport.

Lipoprotein FtsB in Streptococcus pyogenes Binds Ferrichrome in Two Steps with Residues Tyr137 and Trp204 as Critical Ligands