Table 1.
Transmembrane (TM) helices, chlorophylls, and other cofactors of PSII RCs from cyanobacteria and plants1.
| Subunits | TM helices | Chlorophylls | Other cofactors in plant PSII RC | |||||
|---|---|---|---|---|---|---|---|---|
| Cyano | Plant | Cyano | Plant | Carotenoid | Heme | Lipid | Others | |
| A (D1) | 5 | 5 | 4 | 62 | 1 | 3 | 1 Mn4CaO5 | |
| B (CP47) | 6 | 6 | 16 | 16 | 3 | 2 | ||
| C (CP43) | 6 | 6 | 13 | 13 | 3 | 4 | ||
| D (D2) | 5 | 5 | 4 | 2 | 1 | 4 | 1 plastoquinone | |
| E | 1 | 1 | 13 | |||||
| F | 1 | 1 | ||||||
| H | 1 | 1 | 1 | 1 | ||||
| I | 1 | 1 | ||||||
| J | 1 | 1 | ||||||
| K | 1 | 1 | 1 | |||||
| L | 1 | 1 | 1 | |||||
| M | 1 | 1 | ||||||
| O | 0 | 0 | ||||||
| P | 0 | |||||||
| Q | 0 | |||||||
| T | 1 | |||||||
| U | 0 | |||||||
| V | 0 | |||||||
| W | 1 | |||||||
| Tc | 1 | |||||||
| Tn | 0 | |||||||
| X | 1 | 1 | ||||||
| Y | 1 | |||||||
| Z | 1 | 2 | 1 | |||||
| Ycf12 | 1 | |||||||
1The subunit composition and the number of TM helices are based on the structures of PSIIs from Tynechococcus elongatus and spinach (Guskov et al., 2009; Wei et al., 2016). 2These include 4 Chl a and 2 pheophytin. 3This heme is bound by both PsbE and PsbF.