CATH Classification

Domain Context

CATH Clusters

Superfamily Single helix bin
Functional Family

Enzyme Information

7.1.1.6
Plastoquinol--plastocyanin reductase.
based on mapping to UniProt Q93SX0
Plastoquinol + 2 oxidized plastocyanin + 2 H(+)(Side 1) = plastoquinone + 2 reduced plastocyanin + 4 H(+)(Side 2).
-!- Contains two b-type cytochromes, two c-type cytochromes (c(n) and f), and a [2Fe-2S] Rieske cluster. -!- The enzyme plays a key role in photosynthesis, transferring electrons from photosystem II (EC 1.10.3.9) to photosystem I (EC 1.97.1.12). -!- Cytochrome c-552 can act as acceptor instead of plastocyanin, but more slowly. -!- In chloroplasts, protons are translocated through the thylakoid membrane from the lumen to the stroma. -!- The mechanism occurs through the Q cycle as in EC 7.1.1.8 (complex III) and involves electron bifurcation. -!- Formerly EC 1.10.9.1 and EC 1.10.99.1.

UniProtKB Entries (1)

Q93SW9
CYF_NOSS1
Nostoc sp. PCC 7120
Cytochrome f

PDB Structure

PDB 2ZT9
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Structure-Function, Stability, and Chemical Modification of the Cyanobacterial Cytochrome b6f Complex from Nostoc sp. PCC 7120
Baniulis, D., Yamashita, E., Whitelegge, J.P., Zatsman, A.I., Hendrich, M.P., Hasan, S.S., Ryan, C.M., Cramer, W.A.
J.Biol.Chem.