Fig. 4.

Characterization of SMU_63c. (a) Schematic representation of the genetic locus containing smu_63 c. (b and c) Quantitative real-time PCR analysis of smu_63 c expression with and without addition of CSP in THYE medium (b) or XIP in CDM-glucose (c). (d) Western blot densitometry analysis of SMU_63c present in cell surface SDS extracts of S. mutans in THYE, with and without addition of CSP. (e) Western blot densitometry analysis of SMU_63c in concentrated spent medium from CDM-glucose cultures grown with or without XIP. (f) Western blot analysis of WapA in the same samples as (d). (g) Evaluation of the genetic competence of S. mutans WT, ∆smu_63 c mutant, complemented mutant and pBGK integration vector control strain. Error bars represent the mean±sem of three or four independent replicates. Statistical significance was evaluated by Student's t-test or one-way ANOVA.