5CF3

Crystal structures of Bbp from Staphylococcus aureus

Summary for 5CF3

• Entry DOI: 10.2210/pdb5cf3/pdb
• Related: 5CFA
• Descriptor: Bone sialoprotein-binding protein, CALCIUM ION (3 entities in total)
• Functional Keywords: bbp, fibrinogen, sdr, mscramm, protein binding
• Biological source: Staphylococcus aureus
• Cellular location: Secreted, cell wall ; Peptidoglycan-anchor : Q14U76
• Total number of polymer chains: 1
• Total formula weight: 36580.16

Authors

Yu, Y.,Zhang, X.Y.,Gu, J.K. (deposition date: 2015-07-08, release date: 2015-09-23, Last modification date: 2023-11-08)

Primary citation

Zhang, X.Y.,Wu, M.,Zhuo, W.,Gu, J.K.,Zhang, S.S.,Ge, J.P.,Yang, M.J.
Crystal structures of Bbp from Staphylococcus aureus reveal the ligand binding mechanism with Fibrinogen alpha
Protein Cell, 6:757-766, 2015

PubMed 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.

PubMed: 26349459
DOI: 10.1007/s13238-015-0205-x

Experimental method

X-RAY DIFFRACTION (2.031 Å)