Crystal structures of Bbp from Staphylococcus aureus reveal the ligand binding mechanism with Fibrinogen α
Protein & Cell
;
(12): 757-766, 2015.
Article
in English
| WPRIM
| ID: wpr-757190
ABSTRACT
Bone sialoprotein-binding protein (Bbp), a MSCRAMMs (Microbial Surface Components Recognizing Adhesive Matrix Molecules) family protein expressed on the surface of Staphylococcus aureus (S. aureus), mediates adherence to fibrinogen α (Fg α), a component in the extracellular matrix of the host cell and is important for infection and pathogenesis. In this study, we solved the crystal structures of apo-Bbp(273-598) and Bbp(273-598)-Fg α(561-575) complex at a resolution of 2.03 Å and 1.45 Å, respectively. Apo-Bbp(273-598) contained the ligand binding region N2 and N3 domains, both of which followed a DE variant IgG fold characterized by an additional D1 strand in N2 domain and D1' and D2' strands in N3 domain. The peptide mapped to the Fg α(561-575) bond to Bbp(273-598) on the open groove between the N2 and N3 domains. Strikingly, the disordered C-terminus in the apo-form reorganized into a highly-ordered loop and a β-strand G'' covering the ligand upon ligand binding. Bbp(Ala298-Gly301) in the N2 domain of the Bbp(273-598)-Fg α(561-575) complex, which is a loop in the apo-form, formed a short α-helix to interact tightly with the peptide. In addition, Bbp(Ser547-Gln561) in the N3 domain moved toward the binding groove to make contact directly with the peptide, while Bbp(Asp338-Gly355) and Bbp(Thr365-Tyr387) in N2 domain shifted their configurations to stabilize the reorganized C-terminus mainly through strong hydrogen bonds. Altogether, our results revealed the molecular basis for Bbp-ligand interaction and advanced our understanding of S. aureus infection process.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Peptide Fragments
/
Protein Binding
/
Staphylococcus aureus
/
Bacterial Proteins
/
Fibrinogen
/
Carrier Proteins
/
Models, Molecular
/
Chemistry
/
Protein Structure, Tertiary
/
Crystallography, X-Ray
Type of study:
Prognostic study
Language:
English
Journal:
Protein & Cell
Year:
2015
Type:
Article
Similar
MEDLINE
...
LILACS
LIS