Skip to main content
eScholarship
Open Access Publications from the University of California

A unique supramolecular organization of photosystem I in the moss Physcomitrella patens

  • Author(s): Iwai, M
  • Grob, P
  • Iavarone, AT
  • Nogales, E
  • Niyogi, KK
  • et al.
Abstract

© 2018, The Author(s), under exclusive licence to Springer Nature Limited. The photosynthesis machinery in chloroplast thylakoid membranes is comprised of multiple protein complexes and supercomplexes1,2. 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 reinhardtii3. Our results show that the structural organization is unexpectedly different—two rows of the LHCI belt exist as in C. reinhardtii4, 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.

Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.

Main Content
Current View