The oxygen-evolving complex (OEC) of Photosystem II (PS II) in green plants, algae, and cyanobacteria contains a cluster of four manganese atoms as the catalytic site of photo-induced oxidation of water to oxygen. Manganese K-edge X-ray absorption spectroscopy (XAS) studies have been used to help elucidate the structure of this active site as well as the electronic environment around the Mn ions as the OEC accumulates oxidative equivalents. Although chloride was identified as a required cofactor for photosynthetic oxygen evolution over fifty years ago, the location of the chloride cofactor binding site is still unknown. It is thus desirable to probe the halide site directly and clarify its possible proximity to the Mn cluster. This proposal seeks to apply x-ray absorption near edge spectroscopy (XANES) and extended x-ray absorption fine structure (EXAFS) at the chlorine edge in PS II membranes to determine whether Cl- is bound directly to Mn, and its role in the mechanism of photosynthetic water oxidation. Bromide and iodide can be substituted with some (albeit subdued) retention of OEC activity, and thus supporting experiments using Br- and I-- substituted PS II membranes are included in the experimental program.

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR001209-20
Application #
6119631
Study Section
Project Start
1999-03-01
Project End
2000-04-14
Budget Start
1998-10-01
Budget End
1999-09-30
Support Year
20
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Stanford University
Department
Type
DUNS #
800771545
City
Stanford
State
CA
Country
United States
Zip Code
94305
Vickers, Chelsea; Liu, Feng; Abe, Kento et al. (2018) Endo-fucoidan hydrolases from glycoside hydrolase family 107 (GH107) display structural and mechanistic similarities to ?-l-fucosidases from GH29. J Biol Chem 293:18296-18308
Nguyen, Phong T; Lai, Jeffrey Y; Lee, Allen T et al. (2018) Noncanonical role for the binding protein in substrate uptake by the MetNI methionine ATP Binding Cassette (ABC) transporter. Proc Natl Acad Sci U S A 115:E10596-E10604
Aleman, Fernando; Tzarum, Netanel; Kong, Leopold et al. (2018) Immunogenetic and structural analysis of a class of HCV broadly neutralizing antibodies and their precursors. Proc Natl Acad Sci U S A 115:7569-7574
Herrera, Nadia; Maksaev, Grigory; Haswell, Elizabeth S et al. (2018) Elucidating a role for the cytoplasmic domain in the Mycobacterium tuberculosis mechanosensitive channel of large conductance. Sci Rep 8:14566
Lal, Neeraj K; Nagalakshmi, Ugrappa; Hurlburt, Nicholas K et al. (2018) The Receptor-like Cytoplasmic Kinase BIK1 Localizes to the Nucleus and Regulates Defense Hormone Expression during Plant Innate Immunity. Cell Host Microbe 23:485-497.e5
Pluvinage, Benjamin; Grondin, Julie M; Amundsen, Carolyn et al. (2018) Molecular basis of an agarose metabolic pathway acquired by a human intestinal symbiont. Nat Commun 9:1043
Beyerlein, Kenneth R; Jönsson, H Olof; Alonso-Mori, Roberto et al. (2018) Ultrafast nonthermal heating of water initiated by an X-ray Free-Electron Laser. Proc Natl Acad Sci U S A 115:5652-5657
Yoshizawa, Takuya; Ali, Rustam; Jiou, Jenny et al. (2018) Nuclear Import Receptor Inhibits Phase Separation of FUS through Binding to Multiple Sites. Cell 173:693-705.e22
Morrison, Christine N; Spatzal, Thomas; Rees, Douglas C (2017) Correction to Reversible Protonated Resting State of the Nitrogenase Active Site. J Am Chem Soc 139:13958
Remesh, Soumya G; Andreatta, Massimo; Ying, Ge et al. (2017) Unconventional Peptide Presentation by Major Histocompatibility Complex (MHC) Class I Allele HLA-A*02:01: BREAKING CONFINEMENT. J Biol Chem 292:5262-5270

Showing the most recent 10 out of 604 publications