| Abstract |
Aerobic photosynthesis uses water as the terminal electron donor in its electron transfer chain, known as the Z scheme. The Oxygen Evolving Complex, a Mn4O5Ca catalyst in photosystem II (PSII) reduces water to O2. Water channels bring substrate water into the OEC and remove product protons to the lumen. In thermophilic cyanobacteria, three channels have been well characterized. The program MCCE uses Monte Carlo (MC) sampling to determine the Boltzmann distribution of protonation states, side chain positions, and water molecule orientation and occupancy within the protein. The hydrogen bonds made in each accepted MC microstate are determined. These connections are used to trace proton transfer networks in Pisum sativa (Pea) (5xnl) PSII for comparison with earlier studies of T. vulcanus PSII (4UB6). Near the OEC the hydrogen-bonded pathways are remarkably conserved in Pea but the end of the three previously characterized channels diverge from those found in T. vulcanus. Thus, while the region containing the OEC catalyst is highly conserved PSII may provide evidence of the plasticity of proton transfer paths. Supported by DOE BES DE-SC0001423. |
| Authors |
Jose Ortiz-Soto , Benjamin Conrad Romanjenko  , Carmela Guadagno , Divya Kaur  , M. R. Gunner
|
| Journal Info |
Elsevier BV | Biophysical Journal , vol: 123
, iss: 3
, pages: 264a - 264a
|
| Publication Date |
2/1/2024 |
| ISSN |
0006-3495 |
Type |
article |
| Open Access |
closed
|
| DOI |
https://doi.org/10.1016/j.bpj.2023.11.1657 |
| Keywords |
Photosynthetic Acclimation (Score: 0.517386) , Photosystem II (Score: 0.500304)
|
