Characterization of a 41 kDa photoinhibition adduct in isolated photosystem II reaction centres.
When isolated reaction centres of photosystem II are subjected to photoinhibitory illumination, a 41 kDa SDS-PAGE band is observed under all experimental conditions. The same band is also found, together with lower molecular weight fragments of the D1 protein, in whole thylakoids and in all PSII sub-particles investigated up to now. In the case of isolated reaction centres the 41 kDa band is represented by a heterodimer of the D1 polypeptide and the alpha-subunit of cytochrome b559. The cross-linkage between D1 and alpha-cyt b559 involves a region on D1 between the N-terminal residue and Arg-225, and is an early event in photo-induced damage to the D1 protein.
Barbato
R
R
Dipartimento di Biologia, Università di Padova, Italy.
Friso
G
G
Rigoni
F
F
Frizzo
A
A
Giacometti
G M
GM
D015153:Blotting, Western; D003573:Cytochrome b Group / Q000737:chemistry / Q000528:radiation effects*; D008027:Light; D010777:Photochemistry; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000528:radiation effects*; D045332:Photosystem II Protein Complex
D003573:Cytochrome b Group; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; C019313:cytochrome b559