Photosynthetic water oxidation is catalyzed by the Mn4CaO5-cluster1,2 of Photosystem II (PSII) through a linear four oxidation intermediates of Si-state cycle (Si, i = 0-4). The catalyst becomes a Mn4CaO6-cluster in the S3-state by incorporation of additional oxygen O6 nearby a unique central oxo-bridge O53, supporting a dioxygen formation mechanism between O5 and O6. While insertion of the O6...
Robin Owen1, Danny Axford1, Ali Ebrahim1,2, Selina Storm1, Hiroshi Sugimoto3, Kensuke Tono3, Shigeki Owada3 Tadeo Moreno-Chicano2, Richard Strange2, Jonathan Worrall2 , Ivo Tews3 & Michael Hough2
1Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
2School of life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex, CO4 3SQ,...
Metalloproteins, particularly those containing transition metals in high valent states are highly sensitive to redox state changes as a consequence of X-ray exposure during data collection. If not under-stood and interpreted correctly, this site-specific damage may lead to misinterpretation of structural data and mis-assignment of structures to e.g. enzyme mechanistic states. Increasing...
The method of X-ray footprinting mass spectrometry (XFMS) is used to investigate structural features and conformational changes of macromolecules in the solution state. XFMS is an in situ hydroxyl radical (•OH) labeling method; X-ray irradiation dissociates solvent water to produce hydroxyl radicals, which covalently modify side chains which are solvent accessible. More specifically, residues...
