FIG. 1.

Diagram of class I and class II dsrA genes and PCR products. The dsrA ORF is boxed. The partial manX ORF is represented by an open box with a jagged line at the upstream end; the partial HD0770 ORF is represented by an open box with a jagged line at the downstream end. The numbered arrows indicate the direction and position of the dsrA oligonucleotides used for PCR. The proposed signal sequence (ss) is indicated by a shaded box. Curved arrows indicate the polarity of each gene. (A) The PCR products used to construct plasmids pUNCH 1260 and pUNCH 1296 are indicated. (B) The dsrA PCR products are represented by a solid black line followed by a hexahistidine fusion tag depicted by an open box. The PCR-His fusion products were used to produce expression plasmids pUNCH 1250, pUNCH 1293, and pUNCH 1294. Strains and vectors used for PCR are specified to the left of the PCR product. his, hexahistidine, composed of 30 amino acids; P, promoter.