Inactivation of srtA gene of Streptococcus mutans inhibits dextran-dependent aggregation by glucan-binding protein C.
A sortase-deficient mutant of Streptococcus mutans was prepared by insertional inactivation of a sortase gene (srtA). The srtA mutant was defective in cell wall-anchoring of two surface proteins 200 and 75 kDa in size. A previous study has shown that the 200 kDa protein is a surface protein antigen PAc and that the sortase catalyzes cell wall-anchoring of PAc in S. mutans. In this study another surface protein 75 kDa in size was examined by immunologic and physiologic methods. Western blot analysis with a specific antiserum showed that the 75 kDa protein was a surface protein, glucan-binding protein C. The protein was overexpressed under a stress condition including a sublethal concentration of tetracycline. The srtA mutant cells also lost the ability of dextran-dependent aggregation. These results suggest that the S. mutans sortase mediates cell wall-anchoring of the glucan-binding protein C and dextran-dependent aggregation of this organism.
Igarashi
T
T
Department of Oral Microbiology, Showa University School of Dentistry, Tokyo, Japan. Igatakes@dent.showa-u.ac.jp
Asaga
E
E
Sato
Y
Y
Goto
N
N
D018829:Adhesins, Bacterial / Q000235:genetics; D019881:Aminoacyltransferases / Q000235:genetics*; D000942:Antigens, Bacterial / Q000235:genetics; D001422:Bacterial Adhesion / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D003546:Cysteine Endopeptidases; D003911:Dextrans / Q000378:metabolism; D000939:Epitopes / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D020868:Gene Silencing; D005936:Glucans / Q000235:genetics*; D006801:Humans; D037102:Lectins; D008562:Membrane Glycoproteins; D009154:Mutation / Q000235:genetics; D013295:Streptococcus mutans / Q000235:genetics*
D018829:Adhesins, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D003911:Dextrans; D000939:Epitopes; D005936:Glucans; D037102:Lectins; D008562:Membrane Glycoproteins; C055764:S-layer proteins; C037937:glucan-binding proteins; D019881:Aminoacyltransferases; C120542:sortase A; D003546:Cysteine Endopeptidases