Gouaux E, Hobaugh M, Song L
Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, USA.
Protein Sci. 1997 Dec;6(12):2631-5. doi: 10.1002/pro.5560061216.
alpha-Hemolysin from Staphylococcus aureus assembles from a water-soluble, monomeric species to a membrane-bound heptamer on the surface of target cells, creating water-filled channels that lead to cell death and lysis. Staphylococcus aureus also produces the gamma-hemolysin and leukocidin toxins, which function as two component toxins in the disruption and lysis of erythrocytes and leukocytes. Analysis of the aligned sequences of alpha-hemolysin, gamma-hemolysin, and leukocidin in the context of the alpha-hemolysin heptamer structure supports the conclusion that even though the level of sequence identity between alpha-hemolysin and the gamma-hemolysin and leukocidin toxins is in the so-called twilight zone, the three-dimensional structures of the protomers are probably conserved. By analogy with alpha-hemolysin, gamma-hemolysin and leukocidin may also form oligomeric, transmembrane channels in which an antiparallel beta-barrel constitutes the primary membrane-embedded domain.
金黄色葡萄球菌的α-溶血素从水溶性单体形式组装成靶细胞表面的膜结合七聚体，形成充满水的通道，导致细胞死亡和裂解。金黄色葡萄球菌还产生γ-溶血素和杀白细胞素毒素，它们在红细胞和白细胞的破坏和裂解中作为双组分毒素发挥作用。在α-溶血素七聚体结构的背景下对α-溶血素、γ-溶血素和杀白细胞素的比对序列分析支持了这样的结论：尽管α-溶血素与γ-溶血素和杀白细胞素毒素之间的序列同一性水平处于所谓的“模糊区域”，但原体的三维结构可能是保守的。与α-溶血素类似，γ-溶血素和杀白细胞素也可能形成寡聚跨膜通道，其中反平行β-桶构成主要的膜嵌入结构域。
