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-Structure paper
タイトル | Structural basis for cooperative oxygen binding and bracelet-assisted assembly of Lumbricus terrestris hemoglobin. |
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ジャーナル・号・ページ | Sci Rep, Vol. 5, Page 9494, Year 2015 |
掲載日 | 2015年4月21日 |
著者 | Wei-Ting Chen / Yu-Chuen Chen / Horng-Huei Liou / Chih-Yu Chao / |
PubMed 要旨 | The iron-containing hemoglobins (Hbs) are essential proteins to serve as oxygen transporters in the blood. Among various kinds of Hbs, the earthworm Hbs are the champions in carrying oxygen due to ...The iron-containing hemoglobins (Hbs) are essential proteins to serve as oxygen transporters in the blood. Among various kinds of Hbs, the earthworm Hbs are the champions in carrying oxygen due to not only their large size but also the unusually high cooperativity of ligand binding. However, the cooperative oxygen binding mechanisms are still mostly unknown. Here we report the cryo-electron microscopy structure of Lumbricus terrestris Hb in its native, oxygenated state at 9.1 Å resolution, showing remarkable differences from the carbon monoxide-binding X-ray structure. Our structural analysis first indicates that the cooperative ligand binding of L. terrestris Hb requires tertiary and quaternary transitions in the heme pocket and a global subunit movement facilitated by intra-ring and inter-ring contacts. Moreover, the additional sinusoidal bracelet provides the confirmation for the long-standing debate about the additional electron densities absent in the X-ray crystal structure. |
リンク | Sci Rep / PubMed:25897633 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 8.1 Å |
構造データ | |
由来 |
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キーワード | TRANSPORT PROTEIN |