... 310–316.7. Balme, A. , Herva´s,M.,Campos,L .A. ,Sancho,J.,DelaRosa,M .A. & Navarro, J .A. (20 02) A comparative study of the thermalstability of plastocyanin, cytochrome c6 and photosystem I in thermophilic ... at the time of chloroplast origin had poorly definedinteractions between Cyt f and plastocyanin and/ or plasto-cyanin and photosystem I, and subsequently the nature of the interactions in the ... copperligand H 92. R93 has been shown to be essential for the interaction of plastocyanin with photosystem I in Anabaena[15], and is highly conserved in cyanobacterial plastocya-nins. Mutagenesis,...