FIG. 2.

(A) Schematic diagram of the capsule biosynthesis and transport operon intergenic region. The locations of various primers (half-arrows) used in this study are noted below the diagram. The shaded bar is the 134-bp intergenic region between the two start codons of synA and ctrA. Base numbering is from the corresponding transcriptional start sites, which are indicated by bent arrows. The repeats examined in mutagenesis studies are also shown as arrows. The Ω cassette was inserted into the SnaBI site within the 5′ UTR of synA in the two INT1 constructs, whereas the two INT2 constructs were created with the Ω cassette inserted at the start of the coding sequence. In addition, the sequence between primers JS75 and JS74 was deleted in the ΔΩINT1 strain, while the sequence between JS94 and JS93 was removed in the ΔΩINT2 construct. (B) Capsule whole-cell ELISA of wild-type strain NMB and meningococcal mutants ΩINT1, ΩINT2, ΔΩINT1, and ΔΩINT2. An unencapsulated synA::Tn916 mutant (28) was used as the negative control. A ctrA::Tn916 mutant, 700 (30), is included for comparison. Results are shown as the average values from three independent experiments.