| Types | DnaRegion
|
| Roles | CDS
Coding
|
| Sequences | BBa_K1884005_sequence (Version 1)
|
Description
This family represents the D1 protein (also known as PsbA), which forms the reaction core of PSII as a heterodimer with the D2 protein. In higher plants, the N-terminal residues of both proteins, which are exposed to the stromal surface, can be reversibly phosphorylated. After insertion in the membrane, the C-terminal of the D1 protein is cleaved by a C-terminal processing protease to yield the mature protein . This processing is essential for the assembly of a functional 4-atom manganese cluster, which involves binding to a highly conserved C-terminal alanine 344. The Mn cluster is located on the lumenal surface of the D1 and D2 proteins. In addition to the Mn cluster, the D1/D2 core binds to a number of cofactors, including two pheophytin molecules, only one of which is phytochemically active; non-haem iron; and two quinones, Qa (bound to D2) and Qb (bound to D1). Upon light excitation, an electron is transferred from the primary donor (chlorophyll a) via intermediate acceptor pheophytin to the primary quinone Qa, then to the secondary quinone Qb. At the oxidising side of PSII, a redox-active residue in the D1 protein reduces P680, the oxidised tyrosine then withdrawing electrons from a manganese cluster, which in turn withdraw electrons from water, leading to the splitting of water and the formation of molecular oxygen. PSII thus provides a source of electrons that can be used by photosystem I to produce the reducing power (NADPH) required to convert CO2 to glucose.
Source
The DNA sequence of D1 protein is designed by ourselves.
