Location of PsbY in oxygen-evolving photosystem II revealed by mutagenesis and X-ray crystallography.
PsbY is one of the low molecular mass subunits of oxygen-evolving photosystem II (PSII). Its location, however, has not been identified in the current crystal structure of PSII. We constructed a PsbY-deletion mutant of Thermosynechococcus elongatus, crystallized, and analyzed the crystal structure of the mutant PSII dimer. The results obtained showed that PsbY is located in the periphery of PSII close to the alpha- and beta-subunits of cytochrome b559, which corresponded to an unassigned helix in the 3.7A structure of T. vulcanus or helix X2 in the 3.0A structure of T. elongatus. Our results also indicated that the C-terminal loop of PsbY is protruded toward the stromal side, instead of the lumenal side predicted previously.
Kawakami
Keisuke
K
Division of Bioscience, Graduate School of Natural Science and Technology/Faculty of Science, Okayama University, Okayama 700-8530, Japan.
Iwai
Masako
M
Ikeuchi
Masahiko
M
Kamiya
Nobuo
N
Shen
Jian-Ren
JR
D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D018360:Crystallography, X-Ray; D000458:Cyanobacteria; D019281:Dimerization; D008958:Models, Molecular; D016296:Mutagenesis; D045332:Photosystem II Protein Complex / Q000737:chemistry* / Q000235:genetics; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics
D001426:Bacterial Proteins; D045332:Photosystem II Protein Complex; D021122:Protein Subunits