Streptococcus mutans glucan-binding protein-A affects Streptococcus gordonii biofilm architecture.
The glucan-binding protein-A (GbpA) of Streptococcus mutans has been shown to contribute to the architecture of glucan-dependent biofilms formed by this species and influence virulence in a rat model. As S. mutans synthesizes multiple glucosyltransferases and nonglucosyltransferase glucan-binding proteins (GBPs), it is possible that there is functional redundancy that overshadows the full extent of GbpA contributions to S. mutans biology. Glucan-associated properties such as adhesion, aggregation, and biofilm formation were examined independently of other S. mutans GBPs by cloning the gbpA gene into a heterologous host, Streptococcus gordonii, and derivatives with altered or diminished glucosyltransferase activity. The presence of GbpA did not alter dextran-dependent aggregation nor the initial sucrose-dependent adhesion of S. gordonii. However, expression of GbpA altered the biofilm formed by wild-type S. gordonii as well as the biofilm formed by strain CH107 that produced primarily alpha-1,6-linked glucan. Expression of gbpA did not alter the biofilm formed by strain DS512, which produced significantly lower quantities of parental glucan. These data are consistent with a role for GbpA in facilitating the development of biofilms that harbor taller microcolonies via binding to alpha-1,6-linkages within glucan. The magnitude of the GbpA effect appears to be dependent on the quantity and linkage of available glucan.
Banas
Jeffrey A
JA
Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York, USA. jeffrey-banas@uiowa.edu
Fountain
Tracey L
TL
Mazurkiewicz
Joseph E
JE
Sun
Keer
K
Vickerman
M Margaret
MM
D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D002236:Carbohydrate Conformation; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D005456:Fluorescent Dyes; D005936:Glucans / Q000378:metabolism*; D037102:Lectins / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009930:Organic Chemicals; D011994:Recombinant Proteins / Q000378:metabolism; D013194:Staining and Labeling; D013291:Streptococcus / Q000235:genetics / Q000502:physiology*
D001426:Bacterial Proteins; D002352:Carrier Proteins; D005456:Fluorescent Dyes; D005936:Glucans; D037102:Lectins; D009930:Organic Chemicals; D011994:Recombinant Proteins; C103389:SYTO 9; C037937:glucan-binding proteins