Determination of transcriptional start points of the sigH and rshA genes and sequences of their promoter regions. (a) and (b) Determination of the sigH transcription start sites (TSP) by primer extension analysis. The bottom peaks (PEX) represent cDNA synthesized in the reverse transcription using RNA from C. glutamicum (pET2sigH) and C. glutamicum (pET2sigH4), respectively. The smaller peaks were not reproducibly observed in the repeated experiments. The peaks (A, C, G, T) represent the products of sequencing reactions carried out with the same fluorescent-labeled primer as that used for reverse transcription. (c) Nucleotide sequence of the sigH upstream region. TSPs and the proposed −35 and −10 promoter elements are in bold and underlined. Transcription initiation is indicated by the bent arrows. The proposed binding site for the LexA regulator is boxed and the initiation codons (in bold) of the genes sigH and cg0875 are indicated with hollow arrows. (d) Determination of rshA TSP. (e) Nucleotide sequence of the rshA upstream region. The stop codon (in bold) of sigH is indicated with the black dot. Note that the sequences (c) and (e) are complementary and reversed to those deduced from the peaks generated by the sequencer.
Busche et al. BMC Genomics 2012 13:445 doi:10.1186/1471-2164-13-445