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-Structure paper
タイトル | ATP-induced conformational dynamics in the AAA+ motor unit of magnesium chelatase. |
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ジャーナル・号・ページ | Structure, Vol. 18, Issue 3, Page 354-365, Year 2010 |
掲載日 | 2010年3月10日 |
著者 | Joakim Lundqvist / Hans Elmlund / Ragna Peterson Wulff / Lisa Berglund / Dominika Elmlund / Cecilia Emanuelsson / Hans Hebert / Robert D Willows / Mats Hansson / Martin Lindahl / Salam Al-Karadaghi / |
PubMed 要旨 | Mg-chelatase catalyzes the first committed step of the chlorophyll biosynthetic pathway, the ATP-dependent insertion of Mg(2+) into protoporphyrin IX (PPIX). Here we report the reconstruction using ...Mg-chelatase catalyzes the first committed step of the chlorophyll biosynthetic pathway, the ATP-dependent insertion of Mg(2+) into protoporphyrin IX (PPIX). Here we report the reconstruction using single-particle cryo-electron microscopy of the complex between subunits BchD and BchI of Rhodobacter capsulatus Mg-chelatase in the presence of ADP, the nonhydrolyzable ATP analog AMPPNP, and ATP at 7.5 A, 14 A, and 13 A resolution, respectively. We show that the two AAA+ modules of the subunits form a unique complex of 3 dimers related by a three-fold axis. The reconstructions demonstrate substantial differences between the conformations of the complex in the presence of ATP and ADP, and suggest that the C-terminal integrin-I domains of the BchD subunits play a central role in transmitting conformational changes of BchI to BchD. Based on these data a model for the function of magnesium chelatase is proposed. |
リンク | Structure / PubMed:20223218 |
手法 | EM (単粒子) |
解像度 | 7.5 - 14.0 Å |
構造データ | EMDB-1676: CryoEM 3D reconstruction of Rhodobacter capsulatus Mg-chelatase BchID complex in the presence of ADP |
由来 |
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キーワード | LIGASE / BACTERIOCHLOROPHYLL BIOSYNTHESIS / PHOTOSYNTHESIS |