Volume 7, Issue 5, Pages 916-919 (May 2014) Crystal Structure of a Multilayer Packed Major Light-Harvesting Complex: Implications for Grana Stacking in Higher Plants  Wan Tao , Li Mei , Zhao Xuelin , Zhang Jiping , Liu Zhenfeng , Chang Wenrui   Molecular Plant  Volume 7, Issue 5, Pages 916-919 (May 2014) DOI: 10.1093/mp/ssu005 Copyright © 2014 The Authors. All rights reserved. Terms and Conditions

Figure 1 A Structure-Based Model of Grana Stacking. (A–C) Crystal packing in pea LHCII crystals (PDB entry 2BHW). (D) The physiological stacking pattern of LHCII in grana revealed by electron tomography. The red and green masks shown in (C), (D), and (G) were adapted from the electron tomography study reported by Daum et al. (2010), and the material is copyrighted by the American Society of Plant Biologists and is reprinted with permission. (E–G) Crystal packing in our present structure (PDB entry 4LCZ). (A, E): side view of the crystal packing of 2BHW and 4LCZ, respectively. (B, F): schematic representation of the crystal packing of 2BHW and 4LCZ, respectively. In 2BHW, the LHCII trimers are packed in an up-and-down manner and formed limited stromal contacts, while in 4LCZ, a large area of face-to-face stromal contacts was observed. (C, G) Roughly fitting of the crystal packing of 2BHW and 4LCZ into the in situ stacking of LHCII illustrated in (D). It was demonstrated that the packing pattern of 4LCZ can be well fitted into the LHCII stacking pattern in grana observed through electron microscopy (G). (H) Surface charge representation illustrated the negatively charged stromal surface of LHCII. Positively charged regions are shown as blue and negatively charged regions are shown as red. Cations were located in negatively charged regions to screen the net negative charges. (I) Distribution of flexible grana-stacking residues across the stromal surface of LHCII. The residues distribute evenly across the surface, making it brush-like. (J) Illustration of the interactions between stromal residues and cations in neighboring layers in the crystal. (K) A model of grana stacking in grana based on our crystal packing. The negatively charged stromal residues are represented by red sticks. Cations are shown by blue spheres. The positively charged N-terminals are represented in blue. This model highlights the roles of both cations and the N-termini in grana membrane stacking. The salt bridges are illustrated to be the primary attraction forces in stacking. Molecular Plant 2014 7, 916-919DOI: (10.1093/mp/ssu005) Copyright © 2014 The Authors. All rights reserved. Terms and Conditions