α-hemolysin from Staphylococcus aureus:: An archetype of β-barrel, channel-forming toxins
α-hemolysin from Staphylococcus aureus:: An archetype of β-barrel, channel-forming toxins
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DOI：
10.1006/jsbi.1998.3959
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发表时间：
1998-01-01
影响因子：
3
通讯作者：
Gouaux, E
中科院分区：
文献类型：
--
作者：
Gouaux, E
由金黄色葡萄球菌分泌的33.2 kDa水溶性单体α-溶血素在细胞膜上组装形成跨膜七聚体通道。洗涤剂增溶的七聚体的结构已通过X射线晶体学确定至1.9埃分辨率。七聚体具有蘑菇状形状，直径可达100埃，高度可达100埃。横跨分子长度并与分子七重轴重合的是直径范围从近似16埃到近似46埃的充水通道。14链反向平行β-桶，其中两条链由每个亚基贡献，定义了跨膜结构域。在β-桶的外部有一个宽度约为30埃的疏水带，它提供了一个与脂质双层的非极性部分互补的表面。广泛的原聚体-原聚体界面由盐键和氢键以及疏水相互作用组成，这些接触为七聚体在高达65 ℃的SDS溶液中的稳定性提供了分子合理化。掌握了七聚体的结构，我们就可以更好地理解组装蛋白与膜相互作用的机制，并可以假设组装机制。(C)北京：科学出版社.
alpha-Hemolysin, secreted from Staphylococcus aureus as a water-soluble monomer of 33.2 kDa, assembles on cell membranes to form transmembrane, heptameric channels. The structure of the detergent-solubilized heptamer has been determined by X-ray crystallography to 1.9 Angstrom resolution. The heptamer has a mushroom-like shape and measures up to 100 Angstrom in diameter and 100 Angstrom in height. Spanning the length of the molecule and coincident with the molecular sevenfold axis is a water-filled channel that ranges in diameter from similar to 16 to similar to 46 Angstrom. A 14 strand antiparallel beta-barrel, in which two strands are contributed by each subunit, defines the trans-membrane domain. On the exterior of the beta-barrel there is a hydrophobic belt approximately 30 Angstrom in width that provides a surface complementary to the nonpolar portion of the lipid bilayer. The extensive protomer-protomer interfaces are composed of both salt-links and hydrogen bonds, as well as hydrophobic interactions, and these contacts provide a molecular rationalization for the stability of the heptamer in SDS solutions up to 65 degrees C. With the structure of the heptamer in hand, we can better understand the mechanisms by which the assembled protein interacts with the membrane and can postulate mechanisms of assembly. (C) 1998 Academic Press.