1 Answers
1prcM:37-306 5prcM:37-306 1vrnM:37-306 3prcM:37-306 2prcM:37-306 6prcM:37-306 7prcM:37-306 1dxrM:37-306 1dopA:105-296
Photosynthetic reaction centre proteins are main protein components of photosynthetic reaction centres of bacteria and plants. They are transmembrane proteins embedded in the chloroplast thylakoid or bacterial cell membrane.
Plants, algae, and cyanobacteria have one type of PRC for each of its two photosystems. Non-oxygenic bacteria, on the other hand, have an RC resembling either the Photosystem I centre or the Photosystem II centre. In either case, PRCs have two related proteins making up a quasi-symmetrical 5-helical core complex with pockets for pigment binding. The two types are structurally related and share a common ancestor. Each type have different pockets for ligands to accommodate their specific reactions: while Type I RCs use iron sulfur clusters to accept electrons, Type II RCs use quinones. The centre units of Type I RCs also have six extra transmembrane helices for gathering energy.