Structure of bacteriorhodopsin at 1.55 Å resolution
Structure of bacteriorhodopsin at 1.55 Å resolution
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DOI：
10.1006/jmbi.1999.3027
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发表时间：
1999-08-27
影响因子：
5.6
通讯作者：
Lanyi, JK
中科院分区：
文献类型：
--
作者：
Luecke, H;Schobert, B;Lanyi, JK
用立方脂相中生长的晶体的X射线衍射法测定了光驱动离子泵细菌视紫红质及其周围脂基质的原子结构。在胞外区，由蛋白质残基和七个水分子组成的广泛的三维氢键网络从埋藏的视网膜Schiff碱基和质子受体Asp85连接到膜表面。在视网膜结合的Lys216附近，跨膜螺旋G包含一个圆周率凸起，导致非脯氨酸扭结。Ala215和Lys216的主链羰基与细胞质区域的Schiff碱和质子供体Asp96之间的两个埋水分子通过氢键稳定了凸起。结果表明，结合水分子广泛参与了这种七螺旋膜蛋白的结构和功能。一个由18个紧密结合的脂链组成的双层在晶体中的蛋白质周围形成一个环状结构。膜平面上的三聚体之间的接触几乎完全是由脂类介导的。(C)1999年学术出版社。
Th?e atomic structure of the light-driven ion pump bacteriorhodopsin and the surrounding lipid matrix was determined by X-ray diffraction of crystals grown in cubic lipid phase. In the extracellular region, an extensive three-dimensional hydrogen-bonded network of protein residues and seven water molecules leads from the buried retinal Schiff base and the proton acceptor Asp85 to the membrane surface. Near Lys216 where the retinal binds, transmembrane helix G contains a pi-bulge that causes a non-proline kink. The bulge is stabilized by hydrogen-bonding of the main-chain carbonyl groups of Ala215 and Lys216 with two buried water molecules located between the Schiff base and the proton donor Asp96 in the cytoplasmic region. The results indicate extensive involvement of bound water molecules in both the structure and the function of this seven-helical membrane protein. A bilayer of 18 tightly bound lipid chains forms an annulus around the protein in the crystal. Contacts between the trimers in the membrane plane are mediated almost exclusively by lipids. (C) 1999 Academic Press.