Structural variability of plant photosystem II megacomplexes in thylakoid membranes
Language English Country England, Great Britain Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
27598242
DOI
10.1111/tpj.13325
Knihovny.cz E-resources
- Keywords
- Arabidopsis thaliana, clear native polyacrylamide electrophoresis, grana membrane, megacomplex, photosystem II, single particle electron microscopy,
- MeSH
- Arabidopsis metabolism MeSH
- Microscopy, Electron MeSH
- Photosystem II Protein Complex chemistry metabolism ultrastructure MeSH
- Protein Conformation MeSH
- Models, Molecular MeSH
- Protein Multimerization MeSH
- Arabidopsis Proteins metabolism ultrastructure MeSH
- Light-Harvesting Protein Complexes chemistry metabolism ultrastructure MeSH
- Thylakoids metabolism ultrastructure MeSH
- Protein Binding MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Photosystem II Protein Complex MeSH
- Arabidopsis Proteins MeSH
- Light-Harvesting Protein Complexes MeSH
Plant photosystem II (PSII) is organized into large supercomplexes with variable levels of membrane-bound light-harvesting proteins (LHCIIs). The largest stable form of the PSII supercomplex involves four LHCII trimers, which are specifically connected to the PSII core dimer via monomeric antenna proteins. The PSII supercomplexes can further interact in the thylakoid membrane, forming PSII megacomplexes. So far, only megacomplexes consisting of two PSII supercomplexes associated in parallel have been observed. Here we show that the forms of PSII megacomplexes can be much more variable. We performed single particle electron microscopy (EM) analysis of PSII megacomplexes isolated from Arabidopsis thaliana using clear-native polyacrylamide gel electrophoresis. Extensive image analysis of a large data set revealed that besides the known PSII megacomplexes, there are distinct groups of megacomplexes with non-parallel association of supercomplexes. In some of them, we have found additional LHCII trimers, which appear to stabilize the non-parallel assemblies. We also performed EM analysis of the PSII supercomplexes on the level of whole grana membranes and successfully identified several types of megacomplexes, including those with non-parallel supercomplexes, which strongly supports their natural origin. Our data demonstrate a remarkable ability of plant PSII to form various larger assemblies, which may control photochemical usage of absorbed light energy in plants in a changing environment.
References provided by Crossref.org
Unique structural attributes of the PSI-NDH supercomplex in Physcomitrium patens
Unique organization of photosystem II supercomplexes and megacomplexes in Norway spruce
