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Structure of M-LHCII and CP24 complexes in the unstacked C2S2M2-type PSII-LHCII supercomplex from Pisum sativum
Structural highlights
FunctionCB28_PEA The light-harvesting complex (LHC) functions as a light receptor, it captures and delivers excitation energy to photosystems with which it is closely associated.[1] May channel protons produced in the catalytic Mn center of water oxidation into the thylakoid lumen.[2] Publication Abstract from PubMedIn plants, the photosynthetic machinery photosystem II (PSII) consists of a core complex associated with variable numbers of light-harvesting complexes II (LHCIIs). The supercomplex, comprising a dimeric core and two strongly bound and two moderately bound LHCIIs (C2S2M2), is the dominant form in plants acclimated to limited light. Here we report cryo-electron microscopy structures of two forms of C2S2M2 (termed stacked and unstacked) from Pisum sativum at 2.7- and 3.2-angstrom resolution, respectively. In each C2S2M2, the moderately bound LHCII assembles specifically with a peripheral antenna complex CP24-CP29 heterodimer and the strongly bound LHCII, to establish a pigment network that facilitates light harvesting at the periphery and energy transfer into the core. The high mobility of peripheral antennae, including the moderately bound LHCII and CP24, provides insights into functional regulation of plant PSII. Structure and assembly mechanism of plant C2S2M2-type PSII-LHCII supercomplex.,Su X, Ma J, Wei X, Cao P, Zhu D, Chang W, Liu Z, Zhang X, Li M Science. 2017 Aug 25;357(6353):815-820. doi: 10.1126/science.aan0327. PMID:28839073[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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