6CAM

Glucan Binding Protein C of Streptococcus mutans Mediates both Sucrose-Independent and Sucrose-Dependent Adherence

Summary for 6CAM

• Entry DOI: 10.2210/pdb6cam/pdb
• Related: 5UQZ
• Descriptor: Glucan-binding protein C, CALCIUM ION, beta-D-glucopyranose, ... (4 entities in total)
• Functional Keywords: glucan binding protein, salivary agglutinin, beta-supersandwich, sugar binding protein
• Biological source: Streptococcus mutans
• Total number of polymer chains: 1
• Total formula weight: 39653.30

Authors

Schormann, N.,Mieher, J.L.,Deivanayagam, C. (deposition date: 2018-01-31, release date: 2018-05-09, Last modification date: 2023-10-04)

Primary citation

Mieher, J.L.,Larson, M.R.,Schormann, N.,Purushotham, S.,Wu, R.,Rajashankar, K.R.,Wu, H.,Deivanayagam, C.
Glucan Binding Protein C of Streptococcus mutans Mediates both Sucrose-Independent and Sucrose-Dependent Adherence.
Infect. Immun., 86:-, 2018

PubMed Abstract: The high-resolution structure of glucan binding protein C (GbpC) at 1.14 Å, a sucrose-dependent virulence factor of the dental caries pathogen , has been determined. GbpC shares not only structural similarities with the V regions of AgI/II and SspB but also functional adherence to salivary agglutinin (SAG) and its scavenger receptor cysteine-rich domains (SRCRs). This is not only a newly identified function for GbpC but also an additional fail-safe binding mechanism for Despite the structural similarities with antigen I/II (AgI/II) and SspB of , GbpC remains unique among these surface proteins in its propensity to adhere to dextran/glucans. The complex crystal structure of GbpC with dextrose (β-d-glucose; Protein Data Bank ligand BGC) highlights exclusive structural features that facilitate this interaction with dextran. Targeted deletion mutant studies on GbpC's divergent loop region in the vicinity of a highly conserved calcium binding site confirm its role in biofilm formation. Finally, we present a model for adherence to dextran. The structure of GbpC highlights how artfully microbes have engineered the lectin-like folds to broaden their functional adherence repertoire.

PubMed: 29685986
DOI: 10.1128/IAI.00146-18

Experimental method

X-RAY DIFFRACTION (1.75 Å)