start-ver=1.4 cd-journal=joma no-vol=366 cd-vols= no-issue=6463 article-no= start-page=334 end-page=338 dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20191018 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=An oxyl/oxo mechanism for dioxygen bond formation in PSII revealed by X-ray free electron lasers en-subtitle= kn-subtitle= en-abstract= kn-abstract= Photosynthetic water oxidation is catalyzed by the Mn4CaO5 cluster of photosystem II (PSII) with linear progression through five S-state intermediates (S0 to S4). To reveal the mechanism of water oxidation, we analyzed structures of PSII in the S1, S2, and S3 states by x-ray free-electron laser serial crystallography. No insertion of water was found in S2, but flipping of D1 Glu189 upon transition to S3 leads to the opening of a water channel and provides a space for incorporation of an additional oxygen ligand, resulting in an open cubane Mn4CaO6 cluster with an oxyl/oxo bridge. Structural changes of PSII between the different S states reveal cooperative action of substrate water access, proton release, and dioxygen formation in photosynthetic water oxidation. en-copyright= kn-copyright= en-aut-name=SugaMichihiro en-aut-sei=Suga en-aut-mei=Michihiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=AkitaFusamichi en-aut-sei=Akita en-aut-mei=Fusamichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YamashitaKeitaro en-aut-sei=Yamashita en-aut-mei=Keitaro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NakajimaYoshiki en-aut-sei=Nakajima en-aut-mei=Yoshiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=UenoGo en-aut-sei=Ueno en-aut-mei=Go kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=LiHongjie en-aut-sei=Li en-aut-mei=Hongjie kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=YamaneTakahiro en-aut-sei=Yamane en-aut-mei=Takahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=HirataKunio en-aut-sei=Hirata en-aut-mei=Kunio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 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=9 ORCID= en-aut-name=YonekuraShinichiro en-aut-sei=Yonekura en-aut-mei=Shinichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=YuLong-Jiang en-aut-sei=Yu en-aut-mei=Long-Jiang kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=MurakamiHironori en-aut-sei=Murakami en-aut-mei=Hironori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=NomuraTakashi en-aut-sei=Nomura en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 ORCID= en-aut-name=KimuraTetsunari en-aut-sei=Kimura en-aut-mei=Tetsunari kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=14 ORCID= en-aut-name=KuboMinoru en-aut-sei=Kubo en-aut-mei=Minoru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=15 ORCID= en-aut-name=BabaSeiki en-aut-sei=Baba en-aut-mei=Seiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=16 ORCID= en-aut-name=KumasakaTakashi en-aut-sei=Kumasaka en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=17 ORCID= en-aut-name=TonoKensuke en-aut-sei=Tono en-aut-mei=Kensuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=18 ORCID= en-aut-name=YabashiMakina en-aut-sei=Yabashi en-aut-mei=Makina kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=19 ORCID= en-aut-name=IsobeHiroshi en-aut-sei=Isobe en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=20 ORCID= en-aut-name=YamaguchiKizashi en-aut-sei=Yamaguchi en-aut-mei=Kizashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=21 ORCID= en-aut-name=YamamotoMasaki en-aut-sei=Yamamoto en-aut-mei=Masaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=22 ORCID= en-aut-name=AgoHideo en-aut-sei=Ago en-aut-mei=Hideo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=23 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=24 ORCID= affil-num=1 en-affil=Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=RIKEN SPring-8 Center kn-affil= affil-num=4 en-affil=Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=5 en-affil=RIKEN SPring-8 Center kn-affil= affil-num=6 en-affil=Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=7 en-affil=Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=8 en-affil=RIKEN SPring-8 Center kn-affil= affil-num=9 en-affil=Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=10 en-affil=Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=11 en-affil=Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=12 en-affil=Japan Synchrotron Radiation Research Institute kn-affil= affil-num=13 en-affil=RIKEN SPring-8 Center kn-affil= affil-num=14 en-affil=Department of Chemistry, Graduate School of Science, Kobe University kn-affil= affil-num=15 en-affil=RIKEN SPring-8 Center kn-affil= affil-num=16 en-affil=Japan Synchrotron Radiation Research Institute kn-affil= affil-num=17 en-affil=Japan Synchrotron Radiation Research Institute kn-affil= affil-num=18 en-affil=RIKEN SPring-8 Center kn-affil= affil-num=19 en-affil=RIKEN SPring-8 Center kn-affil= affil-num=20 en-affil=Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=21 en-affil=The Institute for Scientific and Industrial Research, Osaka University kn-affil= affil-num=22 en-affil=RIKEN SPring-8 Center kn-affil= affil-num=23 en-affil=RIKEN SPring-8 Center kn-affil= affil-num=24 en-affil=Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University kn-affil= END