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Please use this identifier to cite or link to this item: http://hdl.handle.net/1807/18269

Title: Characterization of PknB, a Putative Eukaryotic-type Serine/threonine Protein Kinase in Streptococcus mutans
Authors: Del Re, Deanna
Advisor: Cvitkovitch, Dennis
Department: Dentistry
Keywords: Oral microbiology
Streptococcus mutans
serine/threonine protein kinase
Issue Date: 13-Jan-2010
Abstract: PknB is a putative transmembrane eukaryotic-type serine/threonine protein kinase (STPK) in the cariogenic bacterium Streptococcus mutans that affects biofilm formation, genetic competence and acid tolerance. PknB contains extracellular penicillin-binding and serine/threonine kinase associated (PASTA) domains predicted to bind the D-alanyl-D-alanine (D-ala-D-ala) dipeptide of unlinked peptidoglycan. D-ala-D-ala elicits responses dependent and independent of the presence of pknB. Biofilm-derived cells of a pknB-deficient mutant (PKNB) exhibited concentration-dependent growth enhancement with D-ala-D-ala, which was not a nutrient response as addition of L-alanine or D-alanine did not give the same results. A total of 77 genes were differentially expressed in PKNB, including 7 with putative functions in fatty acid biosynthesis. PKNB was more sensitive to cell wall- and membrane-targeting antibiotics compared to wild-type. Based on these results, PknB in S. mutans appears to play an important role in cell wall biosynthesis, response to membrane stress and/or regulation of cell membrane composition.
URI: http://hdl.handle.net/1807/18269
Appears in Collections:Master
Faculty of Dentistry - Master theses

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