Publication Date:
2014-03-29
Description:
The light-harvesting core antenna (LH1) and the reaction centre (RC) of purple photosynthetic bacteria form a supramolecular complex (LH1-RC) to use sunlight energy in a highly efficient manner. Here we report the first near-atomic structure, to our knowledge, of a LH1-RC complex, namely that of a Ca(2+)-bound complex from Thermochromatium tepidum, which reveals detailed information on the arrangement and interactions of the protein subunits and the cofactors. The RC is surrounded by 16 heterodimers of the LH1 alphabeta-subunit that form a completely closed structure. The Ca(2+) ions are located at the periplasmic side of LH1. Thirty-two bacteriochlorophyll and 16 spirilloxanthin molecules in the LH1 ring form an elliptical assembly. The geometries of the pigment assembly involved in the absorption characteristics of the bacteriochlorophyll in LH1 and excitation energy transfer among the pigments are reported. In addition, possible ubiquinone channels in the closed LH1 complex are proposed based on the atomic structure.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Niwa, Satomi -- Yu, Long-Jiang -- Takeda, Kazuki -- Hirano, Yu -- Kawakami, Tomoaki -- Wang-Otomo, Zheng-Yu -- Miki, Kunio -- England -- Nature. 2014 Apr 10;508(7495):228-32. doi: 10.1038/nature13197. Epub 2014 Mar 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan [2]. ; 1] Faculty of Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan [2]. ; Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan. ; Faculty of Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24670637" target="_blank"〉PubMed〈/a〉
Keywords:
Bacteriochlorophylls/chemistry/metabolism
;
Calcium/metabolism
;
Chromatiaceae/*chemistry
;
Coenzymes/chemistry/metabolism
;
Crystallography, X-Ray
;
Light-Harvesting Protein Complexes/*chemistry/metabolism
;
Models, Molecular
;
Protein Binding
;
Protein Structure, Quaternary
;
Protein Subunits/chemistry/metabolism
;
Ubiquinone/metabolism
;
Xanthophylls/chemistry/metabolism
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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