Glucan Binding Protein C of Mediates both Sucrose-Independent and Sucrose-Dependent Adherence.
Publication Type:Journal Article
Source:Infect Immun (2018)
<p>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 not only shares structural similarities with the V-regions of AgI/II and SspB, but also functional adherence to SAG and its scavenger receptor cysteine rich domains (SRCRs) which 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, BGC) highlights exclusive structural features that facilitates 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.</p>