Figure 1

Transcriptional analysis of the S.coelicolor cyd operon using S1 nuclease mapping. Strains were grown to mid-late exponential phase prior to oxygen limitation, or the addition of respiratory inhibitors, ZnCl₂ (0.5 mM) or KCN (5 mM), as indicated. RNA was isolated at the indicated time points. Arrows indicate the protected DNA fragments that correspond to the 5' end of transcripts that initiate at cyd_P1 and cyd_P2. Whereas cyd_P2 remains relatively constant, cyd_P1 is induced by oxygen limitation, zinc treatment and cyanide treatment. The position of marker fragments from a HpaII digestion of pBR322 are indicated for oxygen limitation.