FIG. 3.

Nucleotide sequence of the patS upstream region. (A) The primers used for primer extension assays and the putative transcription start sites at −39 and −314 are labeled. The first ATG translation initiation codon is underlined and indicated by +1. (B) Nucleotide sequence comparison of the putative promoter regions of the two early heterocyst-specific genes, patS and hepA. Similar nucleotide sequences centered at about −31 bases upstream of the developmentally regulated transcription start sites are marked by vertical lines.