What is the structure of plastocyanin?

What is the structure of plastocyanin?

Plastocyanin (PC) is a β-sheet protein (Figure 1) with a Cu atom that acts as the redox center. The Cu atom is coordinated to four amino acid residues (H87, H37, S84, and M92) in a distorted tetrahedral geometry.

What is plastoquinone made up of?

Plastoquinone (PQ) is an isoprenoid quinone molecule involved in the electron transport chain in the light-dependent reactions of photosynthesis. The most common form of plastoquinone, known as PQ-A or PQ-9, is a 2,3-dimethyl-1,4-benzoquinone molecule with a side chain of nine isoprenyl units.

Is plastocyanin a globular?

Cytochrome c1 has a globular domain with a C-type heme ligated by histidine and methionine, together with a membrane spanning α-helix.

What is the function of plastoquinone?

Plastoquinone is one of the electron acceptors associated with Photosystem II in photosynthesis. It accepts two electrons and is reduced to Plastoquinol and as such acts as an electron and energy carrier in the electron transport process.

What is plastoquinone plastocyanin?

Plastoquinone is an electron transporter that transports electron from photosystem II to cytochrome b6f. Plastocyanin, on the other hand, is a copper-containing electron carrier protein that accepts electrons from cytochrome b6f and passes to P700+ of photosystem I.

Where is plastoquinone plastoquinone located in chloroplast?

PQ and UQ are localized in different organelles of plant cells. PQ is located on the thylakoids of chloroplasts, while UQ is located on the inner membrane of mitochondria. The locations of PQ and UQ are consistent with their roles in photophosphorylation and oxidative phosphorylation.

How many electrons does plastoquinone carry?

two electrons
Small molecules called plastoquinones are found in substantial numbers in the lamellae. Like the cytochromes, quinones have important roles in carrying electrons between the components of the light reactions. Since they are lipid soluble, they can diffuse through the membrane. They can carry one or two electrons, and,…

Is plastocyanin membrane bound?

Cytochrome b6f complex and P700+ are both membrane-bound proteins with exposed residues on the lumen-side of the thylakoid membrane of chloroplasts.

Where is plastocyanin located in the chloroplast?

Plastocyanin is a 10 kD blue copper protein which is located in the lumen of the thylakoid where it functions as a mobileelectron carrier shuttling electrons from cytochromef to P700 in Photosystem I.

Is plastoquinone mobile carrier?

Yes, plastoquinone is a mobile carrier, involved in the photosynthesis process.

Is plastocyanin a mobile electron carrier?

For thylakoid membranes of higher plants, a long-standing question has been which of the two mobile electron carriers, plastoquinone or plastocyanin, mediates electron transport from stacked grana thylakoids where photosystem II (PSII) is localized to distant unstacked regions of the thylakoids that harbor PSI.

Is plastocyanin an integral membrane protein?

Plastocyanin is a single strand protein, mw 10,500, that plays an integral part in photosynthesis. This protein has a copper center, consisting of one copper atom surrounded by two nitrogen bonds and two sulfur bonds.