FIG. 4.

Folate-binding by FolT homologs from pathogenic Firmicutes expressed in L. lactis. The folT genes from Clostridium novyi and Streptococcus mutans were obtained by PCR from genomic DNA; that of Mycoplasma capricolum was synthesized by GenScript (Piscataway, NJ). Cells harboring pNZ8048 alone (open squares) or containing FolT homologs (filled squares) were assayed for binding of (6S)-[³H]folinic acid (final concentration, 13.5 nM) as in Fig. 2. The arrows show when unlabeled folinic acid was added to give a final concentration of 50 μM.