FIG. 2.

Restriction map of the dsrA region and PCR products. The dsrA ORF is boxed. The restriction sites are indicated. The numbered arrows indicate the direction and position of the dsrA oligonucleotides used for PCR. KS and T7 (promoter) refer to the vector primers used in the vector-anchored PCR reactions. Since oligonucleotides 6 and 7 were deduced from the amino acid sequence of the mature, processed protein, their position was placed just slightly inside the ORF. P, promoter. The jagged lines represent approximately 2 kb of sequence not shown downstream of the dsrA locus. The products of V-A PCR 1 and standard PCR were used to generate plasmids pUNCH 1248 and pUNCH 1260, respectively.