Figure 1.
Characterization of cdt gene products produced by E. coli BL-21(DE3) (pET15bcdt). A) No bacterial extract or total soluble protein extract (10 ng of protein/μl of medium) from A. actinomycetemcomitans Y4, E. coli DH5α (pBluescript II SK+), E. coli DH5α (pCDT1), or E. coli BL-21(DE3) (pET15bcdt) was added to cultures of HeLa cells. *Statistically significant differences, P<0.05. B) SDS-PAGE of total soluble protein from recombinant strains of E. coli containing combinations or individual cdt genes cloned in pET15b. A, B, C: native polypeptides CdtB and CdtC; His: His-tagged polypeptides determined by Western blotting; *truncated CdtA.