Fig. 2.

Schematic representation of the lexA locus in the genome of Synechocystis sp. strain PCC 6803. (A) The lexA gene is represented in black, while the upstream and downstream genes are represented in dark and light gray, respectively. The relative positions of the oligonucleotides SlexAF2 and slr1735R2 are shown as arrowheads. The lower diagram is a magnification of the map represented above, where it is possible to recognize the transcription start point of lexA (the arrow upstream of the gene) identified by Domain et al. (8) and the transcription stop points identified in the present study by 3′ RACE (the black and gray pins are the lexA and slr1735 transcription stop points, respectively). (B) Physical map of the lexA locus in SFM04 (Synechocystis sp. strain PCC 6803 containing a LexA::GFP fusion). The gfp gene is shown in green, the linker between lexA and gfp is in yellow, and the aphA gene (aminoglycoside 3′-phosphotransferase, which confers resistance to kanamycin) is in white. The kanamycin resistance cassette taken from the vector pUC4K is highlighted.