Abstract
A new contact site between the two reaction center polypeptides D 1 and D 2 of photosystem II close to arg 238 and arg 234 respectively is proposed. The amino acid sequences involved are between the 4 th transmembrane and a connecting parallel helix. The sequence includes a tryp sin sensitive site in both polypeptides, the likely cleavage site in the rapid turnover of the D 1 polypeptide and part of the herbicide binding site. The contact site is oriented towards both quinone binding sites Q A and Q B. A folding of the backbone of the amino acid sequences involved is proposed.
Study of the Mn-binding sites in photosystem II using antibodies raised against lumenal regions of the D1 and D2 reaction center proteins