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@article{Suzuki:2013:10.1021/bi301699h,
author = {Suzuki, H and Yu, J and Kobayashi, T and Nakanishi, H and Nixon, PJ and Noguchi, T},
doi = {10.1021/bi301699h},
journal = {BIOCHEMISTRY},
pages = {4748--4757},
title = {Functional Roles of D2-Lys317 and the Interacting Chloride Ion in the Water Oxidation Reaction of Photosystem II As Revealed by Fourier Transform Infrared Analysis},
url = {http://dx.doi.org/10.1021/bi301699h},
volume = {52},
year = {2013}
}
TY - JOUR
AB - Photosynthetic water oxidation in plants andcyanobacteria is catalyzed by a Mn4CaO5 cluster within thephotosystem II (PSII) protein complex. Two Cl− ions boundnear the Mn4CaO5 cluster act as indispensable cofactors, buttheir functional roles remain to be clarified. We haveinvestigated the role of the Cl− ion interacting with D2-K317 (designated Cl-1) by Fourier transform infraredspectroscopy (FTIR) analysis of the D2-K317R mutant ofSynechocystis sp. PCC 6803 in combination with Cl−/NO3−replacement. The D2-K317R mutation perturbed the bands inthe regions of the COO− stretching and backbone amidevibrations in the FTIR difference spectrum upon the S1 → S2 transition. In addition, this mutation altered the 15N isotope-editedNO3− bands in the spectrum of NO3−-treated PSII. These results provide the first experimental evidence that the Cl-1 site iscoupled with the Mn4CaO5 cluster and its interaction is affected by the S1 → S2 transition. It was also shown that a negative bandat 1748 cm−1 arising from COOH group(s) was altered to a positive intensity by the D2-K317R mutation as well as by NO3−treatment, suggesting that the Cl-1 site affects the pKa of COOH/COO− group(s) near the Mn4CaO5 cluster in a commonhydrogen bond network. Together with the observation that the efficiency of the S3 → S0 transition significantly decreased in thecore complexes of D2-K317R upon moderate dehydration, it is suggested that D2-K317 and Cl-1 are involved in a protontransfer pathway from the Mn4CaO5 cluster to the lumen, which functions in the S3 → S0 transition.
AU - Suzuki,H
AU - Yu,J
AU - Kobayashi,T
AU - Nakanishi,H
AU - Nixon,PJ
AU - Noguchi,T
DO - 10.1021/bi301699h
EP - 4757
PY - 2013///
SN - 0006-2960
SP - 4748
TI - Functional Roles of D2-Lys317 and the Interacting Chloride Ion in the Water Oxidation Reaction of Photosystem II As Revealed by Fourier Transform Infrared Analysis
T2 - BIOCHEMISTRY
UR - http://dx.doi.org/10.1021/bi301699h
UR - http://hdl.handle.net/10044/1/28007
VL - 52
ER -
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