start-ver=1.4
cd-journal=joma
no-vol=1797
cd-vols=
no-issue=2
article-no=
start-page=278
end-page=284
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2010
dt-pub=201002
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Structural and functional studies on Ycf12 (Psb30) and PsbZ-deletion mutants from a thermophilic cyanobacterium
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=Ycf12 (Psb30) and PsbZ are two low molecular weight subunits of photosystem II (PSII), with one and two trans-membrane helices, respectively. In order to study the functions of these two subunits from a structural point of view, we constructed deletion mutants lacking either Ycf12 or PsbZ from Thermosynechococcus elongatus, and purified, crystallized and analyzed the structure of PSII dimer from the two mutants. Our results showed that Ycf12 is located in the periphery of PSII, close to PsbK, PsbZ and PsbJ, and corresponded to the unassigned helix X1 reported previously, in agreement with the recent structure at 2.9 Å resolution (A. Guskov, J. Kern, A. Gabdulkhakov, M. Broser, A. Zouni, W. Saenger, Cyanobacterial photosystem II at 2.9 Å resolution: role of quinones, lipids, channels and chloride, Nat. Struct. Mol. Biol. 16 (2009) 334–342). On the other hand, crystals of PsbZ-deleted PSII showed a remarkably different unit cell constants from those of wild-type PSII, indicating a role of PsbZ in the interactions between PSII dimers within the crystal. This is the first example for a different arrangement of PSII dimers within the cyanobacterial PSII crystals. PSII dimers had a lower oxygen-evolving activity from both mutants than that from the wild type. In consistent with this, the relative content of PSII in the thylakoid membranes was lower in the two mutants than that in the wild type. These results suggested that deletion of both subunits affected the PSII activity, thereby destabilized PSII, leading to a decrease in the PSII content in vivo. While PsbZ was present in PSII purified from the Ycf12-deletion mutant, Ycf12 was present in crude PSII but absent in the finally purified PSII from the PsbZ-deletion mutant, indicating a preferential, stabilizing role of PsbZ for the binding of Ycf12 to PSII. These results were discussed in terms of the PSII crystal structure currently available
en-copyright=
kn-copyright=

en-aut-name=TakasakaKenji
en-aut-sei=Takasaka
en-aut-mei=Kenji
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
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=2
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=3
ORCID=

en-aut-name=KawakamiKeisuke
en-aut-sei=Kawakami
en-aut-mei=Keisuke
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

en-aut-name=OhmoriYukari
en-aut-sei=Ohmori
en-aut-mei=Yukari
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=5
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=6
ORCID=

en-aut-name=TakahashiYuichiro
en-aut-sei=Takahashi
en-aut-mei=Yuichiro
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=7
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=8
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=9
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 Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science

affil-num=3
en-affil=
kn-affil=Department of Chemistry, Graduate School of Science, Osaka City University

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=Division of Bioscience, Graduate School of Natural Science and Technology/Faculty of Science; Okayama University

affil-num=6
en-affil=
kn-affil=Department of Life Sciences (Biology), Graduate School of Arts and Science, The University of Tokyo

affil-num=7
en-affil=
kn-affil=Division of Bioscience, Graduate School of Natural Science and Technology/Faculty of Science; Okayama University

affil-num=8
en-affil=
kn-affil=Department of Chemistry, Graduate School of Science, Osaka City University

affil-num=9
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=Ycf12
kn-keyword=Ycf12
en-keyword=PsbZ
kn-keyword=PsbZ
en-keyword=Oxygen evolution
kn-keyword=Oxygen evolution
END