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一个师兄4年2篇nature1篇Science
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此师兄名严汉池，原导师为中科院生物物理所常文瑞院士，现为施一公
Crystal structure of spinach major light-harvesting complex at 2.72 A resolution. （菠菜主要捕光复合物）（被引次数332）
[My paper] Zhenfeng Liu, Hanchi Yan, Kebin Wang, Tingyun Kuang, Jiping Zhang, Lulu Gui, Xiaomin An, Wenrui Chang
National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, People's Republic of China.
The major light-harvesting complex of photosystem II (LHC-II) serves as the principal solar energy collector in the photosynthesis of green plants and presumably also functions in photoprotection under high-light conditions. Here we report the first X-ray structure of LHC-II in icosahedral proteoliposome assembly at atomic detail. One asymmetric unit of a large R32 unit cell contains ten LHC-II monomers. The 14 chlorophylls (Chl) in each monomer can be unambiguously distinguished as eight Chla and six Chlb molecules. Assignment of the orientation of the transition dipole moment of each chlorophyll has been achieved. All Chlb are located around the interface between adjacent monomers, and together with Chla they are the basis for efficient light harvesting. Four carotenoid-binding sites per monomer have been observed. The xanthophyll-cycle carotenoid at the monomer-monomer interface may be involved in the non-radiative dissipation of excessive energy, one of the photoprotective strategies that have evolved in plants.
Structural analysis of a rhomboid family intramembrane protease reveals a gating mechanism for substrate entry. （菱形家族膜内在蛋白酶）（被引次数36）
[My paper] Zhuoru Wu, Nieng Yan, Liang Feng, Adam Oberstein, Hanchi Yan, Rosanna P Baker, Lichuan Gu, Philip D Jeffrey, Sinisa Urban, Yigong Shi
Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University.
Intramembrane proteolysis regulates diverse biological processes. Cleavage of substrate peptide bonds within the membrane bilayer is catalyzed by integral membrane proteases. Here we report the crystal structure of the transmembrane core domain of GlpG, a rhomboid-family intramembrane serine protease from Escherichia coli. The protein contains six transmembrane helices, with the catalytic Ser201 located at the N terminus of helix alpha4 approximately 10 A below the membrane surface. Access to water molecules is provided by a central cavity that opens to the extracellular region and converges on Ser201. One of the two GlpG molecules in the asymmetric unit has an open conformation at the active site, with the transmembrane helix alpha5 bent away from the rest of the molecule. Structural analysis suggests that substrate entry to the active site is probably gated by the movement of helix alpha5.
3. Biochem Biophys Res Commun. 2007 Feb 7; : 17303080 (P,S,G,E,B,D)
Two lutein molecules in LHCII have different conformations and functions: Insights into the molecular mechanism of thermal dissipation in plants. （叶黄素与植物热耗散）（被引3次，其中一次为07年nature文章引用）
National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences (CAS), Beijing 100101, China; Graduate University of the CAS, Beijing 100049, China.
When LHCII forms aggregates, the internal conformational changes will result in chlorophyll fluorescence quenching. Uncovering the molecular mechanism of this phenomenon will help us to understand how plants dissipate the excess excitation energy through non-photochemical quenching (NPQ) process. The crystal structure of spinach and pea LHCII have been published, and recently, we solved another crystal structure of LHCII from cucumber at 2.66A resolution. Here we present the first direct structural evidence indicating that the two lutein(Lut) molecules bound in each LHCII monomer have different conformations, Lut621 has a more twisted conformation than that of Lut620. The intimate interaction between the Lut620 and Chla612/Chla611 dimer leads to form a hetero-trimer, which is considered to be a potential quenching site. We also discovered that the dehydration of the LHCII crystals resulted in a notable shrinkage of the crystal unit cell dimensions which was accompanied by a red-shift of the fluorescence emission spectra of the crystals. These phenomena suggest the changes in the crystal packing during dehydration might be the cause of internal conformational changes within LHCII. We proposed a conformational change related NPQ model based on the structure analysis.
Structure of a site-2 protease family intramembrane metalloprotease. （金属蛋白酶）（引用次数9，其中一次为08年Science文章引用）
Regulated intramembrane proteolysis by members of the site-2 protease (S2P) family is an important signaling mechanism conserved from bacteria to humans. Here we report the crystal structure of the transmembrane core domain of an S2P metalloprotease from Methanocaldococcus jannaschii. The protease consists of six transmembrane segments, with the catalytic zinc atom coordinated by two histidine residues and one aspartate residue approximately 14 angstroms into the lipid membrane surface. The protease exhibits two distinct conformations in the crystals. In the closed conformation, the active site is surrounded by transmembrane helices and is impermeable to substrate peptide; water molecules gain access to zinc through a polar, central channel that opens to the cytosolic side. In the open conformation, transmembrane helices alpha1 and alpha6 separate from each other by 10 to 12 angstroms, exposing the active site to substrate entry. The structure reveals how zinc embedded in an integral membrane protein can catalyze peptide cleavage.
https://blog.sciencenet.cn/blog-200233-204108.html
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