FIG. 3.

Promoter determination. Panel A: DNA sequence and transcription initiation sites (in boldface) of the Porf3 and PabiK promoters. The −35 and −10 regions, the ribosome binding site of abiK, and the start codons of orf3 and abiK are in capital letters. Nucleic acids that are identical to the consensus sequence are underlined. The coordinates correspond to the DNA sequence of pSRQ800 (accession no. U35629). Panel B: primer extension analysis of the Porf3 promoter. Total RNA from an L. lactis MG1363 strain carrying the pSRQ817 plasmid was purified, and primer extension was performed as described in Materials and Methods. The lower-strand DNA sequence shown on the left was obtained with the same primer in a T7-based sequencing reaction. The −10 box is highlighted in boldface. The transcription initiation start site is indicated by an arrow.