start-ver=1.4
cd-journal=joma
no-vol=1807
cd-vols=
no-issue=3
article-no=
start-page=319
end-page=325
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2011
dt-pub=201103
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Roles of PsbI and PsbM in photosystem II dimer formation and stability studied by deletion mutagenesis and X-ray crystallography
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=PsbM and PsbI are two low molecular weight subunits of photosystem II (PSII), with PsbM being located in the center, and PsbI in the periphery, of the PSII dimer. In order to study the functions of these two subunits from a structural point of view, we crystallized and analyzed the crystal structure of PSII dimers from two mutants lacking either PsbM or PsbI. Our results confirmed the location of these two subunits in the current crystal structure, as well as their absence in the respective mutants. The relative contents of PSII dimers were found to be decreased in both mutants, with a concomitant increase in the amount of PSII monomers, suggesting a destabilization of PSII dimers in both of the mutants. On the other hand, the accumulation level of the overall PSII complexes in the two mutants was similar to that in the wild-type strain. Treatment of purified PSII dimers with lauryldimethylamine N-oxide at an elevated temperature preferentially disintegrated the dimers from the PsbM deletion mutant into monomers and CP43-less monomers, whereas no significant degradation of the dimers was observed from the PsbI deletion mutant. These results indicate that although both PsbM and PsbI are required for the efficient formation and stability of PSII dimers in vivo, they have different roles, namely, PsbM is required directly for the formation of dimers and its absence led to the instability of the dimers accumulated. On the other hand, PsbI is required in the assembly process of PSII dimers in vivo; once the dimers are formed, PsbI was no longer required for its stability.
en-copyright=
kn-copyright=

en-aut-name=KawakamiKeisuke
en-aut-sei=Kawakami
en-aut-mei=Keisuke
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=UmenaYasufumi
en-aut-sei=Umena
en-aut-mei=Yasufumi
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=IwaiMasako
en-aut-sei=Iwai
en-aut-mei=Masako
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=KawabataYousuke
en-aut-sei=Kawabata
en-aut-mei=Yousuke
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

en-aut-name=IkeuchiMasahiko
en-aut-sei=Ikeuchi
en-aut-mei=Masahiko
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=5
ORCID=

en-aut-name=KamiyaNobuo
en-aut-sei=Kamiya
en-aut-mei=Nobuo
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=6
ORCID=

en-aut-name=ShenJian-Ren
en-aut-sei=Shen
en-aut-mei=Jian-Ren
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=7
ORCID=

affil-num=1
en-affil=
kn-affil=Division of Bioscience, Graduate School of Natural Science and Technology/Faculty of Science, Okayama University

affil-num=2
en-affil=
kn-affil=Department of Chemistry, Graduate School of Science, Osaka City University

affil-num=3
en-affil=
kn-affil=Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science

affil-num=4
en-affil=
kn-affil=Division of Bioscience, Graduate School of Natural Science and Technology/Faculty of Science, Okayama University

affil-num=5
en-affil=
kn-affil=Department of Life Sciences (Biology), Graduate School of Arts and Science, The University of Tokyo

affil-num=6
en-affil=
kn-affil=Department of Chemistry, Graduate School of Science, Osaka City University

affil-num=7
en-affil=
kn-affil=Division of Bioscience, Graduate School of Natural Science and Technology/Faculty of Science, Okayama University
en-keyword=Photosystem II
kn-keyword=Photosystem II
en-keyword=Mutant
kn-keyword=Mutant
en-keyword=Crystal structure
kn-keyword=Crystal structure
en-keyword=PsbM
kn-keyword=PsbM
en-keyword=PsbI
kn-keyword=PsbI
en-keyword=Oxygen evolution
kn-keyword=Oxygen evolution
END