FIG. 1.

A schematic representation of pAL2-HtrA plasmid used for expression of the htrA gene in S. pneumoniae. The pAL2-HtrA plasmid was modified from pAL2 plasmid (3) as explained in Materials and Methods. Arrows indicate the locations and orientations of open reading frames. The nucleotide sequence shows the region between the ami promoter and the start codon of htrA. The gram-positive ribosome-binding site is shown in bold and uppercase characters, the htrA start codon is shown in uppercase characters, and restriction sites are underlined. Em-R, erythromycin resistance gene; Cm-R, chloramphenicol resistance gene.