Abstract
Photosystem II (PSII) catalyzes the photo-oxidation of water to molecular oxygen and protons. The water splitting reaction occurs inside the oxygen-evolving complex (OEC) via a Mn4CaO5 cluster. To elucidate the reaction mechanism, detailed structural information for each intermediate state of the OEC is required. Despite the current high-resolution crystal structure of PSII at 1.85 Å and other efforts to follow the structural changes of the Mn4CaO5 cluster using X-ray free electron laser (XFEL) crystallography in addition to spectroscopic methods, many details about the reaction mechanism and conformational changes in the catalytic site during water oxidation still remain elusive. In this study, we present a rarely found successful application of the conventional macroseeding method to a large membrane protein like the dimeric PSII core complex (dPSIIcc). Combining microseeding with macroseeding crystallization techniques allowed us to reproducibly grow large dPSIIcc crystals with a size of ∼3 mm. These large crystals will help improve the data collected from spectroscopic methods like polarized extended X-ray absorption fine structure (EXAFS) and single crystal electron paramagnetic resonance (EPR) techniques and are a prerequisite for determining a three-dimensional structure using neutron diffraction.
| Original language | English |
|---|---|
| Pages (from-to) | 85-94 |
| Number of pages | 10 |
| Journal | Crystal Growth and Design |
| Volume | 18 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 3 2018 |
Funding
We acknowledge access to beamlines of the BESSY II storage ring (Berlin, Germany) via the Joint Berlin MX-Laboratory sponsored by the Helmholtz Zentrum Berlin für Materialien und Energie, the Freie Universitaẗ Berlin, the Humboldt-Universitaẗ zu Berlin, the Max-Delbrück-Centrum and the Leibniz-Institut für Molekulare Pharmakologie. We thank Dr. Martin Bommer for his support at BESSY and for helping in structure analyses, Ina Seuffert for technical assistance. We thank also the support staff at beamline 14.1 at the BESSY II and at MaNDi instrument at ORNL. *(R.H.) Phone; +49 30 2093 47933; e-mail: [email protected]. *(A.Z.) Phone: +49 30 2093 47930; e-mail: [email protected]. ORCID Rana Hussein: 0000-0001-6292-2375 Mohamed Ibrahim: 0000-0002-1431-9755 Frank Müh: 0000-0002-8818-2616 Junko Yano: 0000-0001-6308-9071 Holger Dobbek: 0000-0002-4122-3898 Athina Zouni: 0000-0003-0561-6990 Funding This work was funded by the Human Frontiers Science Project Award No. RGP0063/2013 310 (R.H., A.Z, J.Y.), by Sonderforschungsbereich Sfb1078 (Humboldt Universitaẗ Berlin), Project A5 (MI, A.Z., H.D.), by Director, Office of Science, Office of Basic Energy Sciences (OBES), Division of Chemical Sciences, Geosciences, and Biosciences (CSGB) of the Department of Energy (DOE) under contract DE-AC02− 05CH11231 (J.Y., V.K.Y.) and by National Institutes of Health (NIH) Grant GM055302 (V.K.Y.). A portion of this research used resources at the Spallation Neutron Source a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Notes The authors declare no competing financial interest.
| Funders | Funder number |
|---|---|
| Leibniz-Institut für Molekulare Pharmakologie | |
| OBES | |
| Sonderforschungsbereich Sfb1078 | |
| National Institutes of Health | GM055302 |
| U.S. Department of Energy | DE-AC02− 05CH11231 |
| Office of Science | |
| Basic Energy Sciences | |
| Helmholtz-Zentrum Berlin für Materialien und Energie | |
| Chemical Sciences, Geosciences, and Biosciences Division |