Open AccessA Truncated Mutant of the Extrinsic 23-kDa Protein that Absolutely Requires the Extrinsic 17-kDa Protein for Ca2+ Retention in Photosystem II
Author(s) -
Kentaro Ifuku,
Fumihiko Sato
Publication year - 2002
Publication title -
plant and cell physiology/plant and cell physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.975
H-Index - 152
eISSN - 1471-9053
pISSN - 0032-0781
DOI - 10.1093/pcp/pcf136
Subject(s) - photosystem ii , mutant , photosystem i , photosynthesis , oxygen evolution , chemistry , biophysics , biochemistry , cofactor , photosystem , oxygen , biology , enzyme , gene , electrode , electrochemistry , organic chemistry
One function of the extrinsic 23-kDa protein in photosystem II (OEC23) is to retain Ca(2+ )and Cl(-), two essential cofactors for photosynthetic oxygen evolution. A truncated mutant of OEC23 (OEC23 Delta19) revealed that 19 residues of the N-terminus of OEC23 were necessary for Ca(2+ )retention but not for its proper interaction with OEC17, the extrinsic 17-kDa protein in photosystem II. The lost ability of OEC23 Delta19 to reconstitute the oxygen-evolving activity was partially restored by OEC17 binding, suggesting the involvement of OEC17 in Ca(2+ )retention in photosystem II.