FIG. 1.

Schematic representation of the S. pneumoniae R6 lic2 operon and inactivation constructs. The genetic organization of the tacF, licD1, and licD2 genes forming the lic2 operon is presented. Black bars show the extent of deletions in strains R6Cho⁻ΔlicD1D2 and R6Cho⁻Δlic2. The indicated parts of the genes were replaced by a kanamycin resistance gene. The internal region of tacF used to inactivate the gene by insertion-duplication in strain R6Cho⁻spr1150ID is shown by a gray bar. The same constructs were applied to inactivate genes in a different genetic background.