FIG 1.

The chiA gene and predicted features of the ChiA protein. (A) Map of the chiA region. Numbers below the map refer to kilobase pairs of sequence. The regions of DNA carried by the plasmids pSSK05 (used for complementation), pSSK07 (used for expression of recombinant ChiA in E. coli), and pSAM1 (used for insertional mutagenesis of chiA) are indicated beneath the map. (B) Predicted features of the ChiA protein. SPI, type I signal peptide. GH18N and GH18C, glycohydrolase 18 family domains located near the amino and carboxy termini, respectively. CTD, C-terminal domain involved in secretion by the type IX secretion system. Arrows denote approximate sites of apparent proteolytic processing, and numbers indicate approximate amino acid ranges for each predicted domain.