6mem

Publication Abstract from PubMed

The photosynthesis machinery in chloroplast thylakoid membranes is comprised of multiple protein complexes and supercomplexes(1,2). Here, we show a novel supramolecular organization of photosystem I (PSI) in the moss Physcomitrella patens by single-particle cryo-electron microscopy. The moss-specific light-harvesting complex (LHC) protein Lhcb9 is involved in this PSI supercomplex, which has been shown to have a molecular density similar to that of the green alga Chlamydomonas reinhardtii(3). Our results show that the structural organization is unexpectedly different-two rows of the LHCI belt exist as in C. reinhardtii(4), but the outer one is shifted toward the PsaK side. Furthermore, one trimeric LHC protein and one monomeric LHC protein position alongside PsaL/K, filling the gap between these subunits and the outer LHCI belt. We provide evidence showing that Lhcb9 is a key factor, acting as a linkage between the PSI core and the outer LHCI belt to form the unique supramolecular organization of the PSI supercomplex in P. patens.

A unique supramolecular organization of photosystem I in the moss Physcomitrella patens.,Iwai M, Grob P, Iavarone AT, Nogales E, Niyogi KK Nat Plants. 2018 Nov;4(11):904-909. doi: 10.1038/s41477-018-0271-1. Epub 2018 Oct, 29. PMID:30374090^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.