TABLE 3.
Presence and function of the CCM transcriptional regulators in Microcystis and three model cyanobacterial strainsa
| Transcriptional regulator | Location in genome | Function |
|||
|---|---|---|---|---|---|
| Microcystis (17; this study) | Synechocystis PCC 6803 (29, 53) | Synechococcus PCC 7002 (50) | Synechococcus PCC 7942 (46, 54) | ||
| CcmR | Upstream of high-affinity CO2 uptake operon | Repressor/activator of cmpABCD operon (BCT1) | Repressor of sbtA and high-affinity CO2 uptake operon (not bicA) | Repressor of sbtA and bicA (possibly high-affinity CO2 uptake operon) | – |
| CcmR2 | Upstream of bicA-sbtA operon | Repressor/activator of bicA-sbtA operon | – | – | – |
| CmpR | Upstream of cmpABCD operon (BCT1) or separate location | – | Activator of cmpABCD operon | – | Activator of cmpABCD operon (possibly a repressor of sbtA and high-affinity CO2 uptake operon) |
a
The source or reference(s) are indicated in parentheses in the headings for each column of data. A dash (−) indicates that the transcriptional regulator is absent.