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OHP1, OHP2, and HCF244 Form a Transient Functional Complex with the Photosystem II Reaction Center.
- Source :
-
Plant physiology [Plant Physiol] 2019 Jan; Vol. 179 (1), pp. 195-208. Date of Electronic Publication: 2018 Nov 05. - Publication Year :
- 2019
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Abstract
- The reaction center (RC) of photosystem II (PSII), which is composed of D1, D2, PsbI, and cytochrome b559 subunits, forms at an early stage of PSII biogenesis. However, it is largely unclear how these components assemble to form a functional unit. In this work, we show that synthesis of the PSII core proteins D1/D2 and formation of the PSII RC is blocked specifically in the absence of ONE-HELIX PROTEIN1 (OHP1) and OHP2 proteins in Arabidopsis ( Arabidopsis thaliana ), indicating that OHP1 and OHP2 are essential for the formation of the PSII RC. Mutagenesis of the chlorophyll-binding residues in OHP proteins impairs their function and/or stability, suggesting that they may function in the binding of chlorophyll in vivo. We further show that OHP1, OHP2, and HIGH CHLOROPHYLL FLUORESCENCE244 (HCF244), together with D1, D2, PsbI, and cytochrome b559 , form a complex. We designated this complex the PSII RC-like complex to distinguish it from the RC subcomplex in the intact PSII complex. Our data imply that OHP1, OHP2, and HCF244 are present in this PSII RC-like complex for a limited time at an early stage of PSII de novo assembly and of PSII repair under high-light conditions. In a subsequent stage of PSII biogenesis, OHP1, OHP2, and HCF244 are released from the PSII RC-like complex and replaced by the other PSII subunits. Together with previous reports on the cyanobacterium Synechocystis , our results demonstrate that the process of PSII RC assembly is highly conserved among photosynthetic species.<br /> (© 2019 American Society of Plant Biologists. All Rights Reserved.)
- Subjects :
- Amino Acid Sequence
Arabidopsis Proteins genetics
Arabidopsis Proteins metabolism
Chlorophyll Binding Proteins genetics
Chlorophyll Binding Proteins metabolism
Eukaryotic Initiation Factors genetics
Eukaryotic Initiation Factors metabolism
Kinetics
Models, Molecular
Mutagenesis, Site-Directed
Photosynthesis
Photosystem II Protein Complex metabolism
Sequence Alignment
Thylakoids metabolism
Arabidopsis metabolism
Arabidopsis Proteins physiology
Chlorophyll Binding Proteins physiology
Eukaryotic Initiation Factors physiology
Photosystem II Protein Complex physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1532-2548
- Volume :
- 179
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Plant physiology
- Publication Type :
- Academic Journal
- Accession number :
- 30397023
- Full Text :
- https://doi.org/10.1104/pp.18.01231